diff --git a/TaxBaik.Application/DependencyInjection.cs b/TaxBaik.Application/DependencyInjection.cs
index ef420d6..05f1af9 100644
--- a/TaxBaik.Application/DependencyInjection.cs
+++ b/TaxBaik.Application/DependencyInjection.cs
@@ -20,6 +20,11 @@ public static class DependencyInjection
         services.AddScoped<ConsultationService>();
         services.AddScoped<TaxFilingService>();
         services.AddScoped<CompanyService>();
+        services.AddScoped<TaxProfileService>();
+        services.AddScoped<TaxFilingScheduleService>();
+        services.AddScoped<ConsultingActivityService>();
+        services.AddScoped<ContractService>();
+        services.AddScoped<RevenueTrackingService>();
         return services;
     }
 }
diff --git a/TaxBaik.Application/Services/ConsultingActivityService.cs b/TaxBaik.Application/Services/ConsultingActivityService.cs
new file mode 100644
index 0000000..0a3d98d
--- /dev/null
+++ b/TaxBaik.Application/Services/ConsultingActivityService.cs
@@ -0,0 +1,47 @@
+namespace TaxBaik.Application.Services;
+
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class ConsultingActivityService(IConsultingActivityRepository repository)
+{
+    public async Task<int> CreateAsync(int clientId, string activityType, DateTime activityDate,
+        string description, int? consultantId = null, DateTime? nextFollowupDate = null, CancellationToken ct = default)
+    {
+        if (clientId <= 0)
+            throw new ValidationException("유효한 고객을 선택하세요.");
+        if (string.IsNullOrWhiteSpace(activityType))
+            throw new ValidationException("활동 유형을 입력하세요.");
+        if (string.IsNullOrWhiteSpace(description))
+            throw new ValidationException("활동 내용을 입력하세요.");
+
+        var activity = new ConsultingActivity
+        {
+            ClientId = clientId,
+            ActivityType = activityType.Trim(),
+            ActivityDate = activityDate,
+            Description = description.Trim(),
+            AssignedConsultantId = consultantId,
+            NextFollowupDate = nextFollowupDate,
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        return await repository.CreateAsync(activity, ct);
+    }
+
+    public async Task<IEnumerable<ConsultingActivity>> GetByClientIdAsync(int clientId, CancellationToken ct = default) =>
+        await repository.GetByClientIdAsync(clientId, ct);
+
+    public async Task<IEnumerable<ConsultingActivity>> GetPendingFollowupsAsync(CancellationToken ct = default) =>
+        await repository.GetPendingFollowupsAsync(ct);
+
+    public async Task<IEnumerable<ConsultingActivity>> GetConsultantActivityAsync(int consultantId, DateTime fromDate, CancellationToken ct = default) =>
+        await repository.GetByConsultantAsync(consultantId, fromDate, ct);
+
+    public async Task UpdateAsync(int id, string? outcome, DateTime? nextFollowupDate, CancellationToken ct = default)
+    {
+        var activity = new ConsultingActivity { Id = id, Outcome = outcome, NextFollowupDate = nextFollowupDate, UpdatedAt = DateTime.UtcNow };
+        await repository.UpdateAsync(activity, ct);
+    }
+}
diff --git a/TaxBaik.Application/Services/ContractService.cs b/TaxBaik.Application/Services/ContractService.cs
new file mode 100644
index 0000000..f902b8f
--- /dev/null
+++ b/TaxBaik.Application/Services/ContractService.cs
@@ -0,0 +1,50 @@
+namespace TaxBaik.Application.Services;
+
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class ContractService(IContractRepository repository)
+{
+    public async Task<int> CreateAsync(int clientId, string contractNumber, string serviceType,
+        DateTime startDate, decimal? monthlyFee = null, decimal? totalAmount = null, CancellationToken ct = default)
+    {
+        if (clientId <= 0)
+            throw new ValidationException("유효한 고객을 선택하세요.");
+        if (string.IsNullOrWhiteSpace(contractNumber))
+            throw new ValidationException("계약 번호를 입력하세요.");
+        if (string.IsNullOrWhiteSpace(serviceType))
+            throw new ValidationException("서비스 유형을 입력하세요.");
+
+        var contract = new Contract
+        {
+            ClientId = clientId,
+            ContractNumber = contractNumber.Trim(),
+            ServiceType = serviceType.Trim(),
+            ContractDate = DateTime.Today,
+            StartDate = startDate,
+            MonthlyFee = monthlyFee,
+            TotalAmount = totalAmount,
+            Status = "active",
+            PaymentStatus = "pending",
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        return await repository.CreateAsync(contract, ct);
+    }
+
+    public async Task<Contract?> GetByIdAsync(int id, CancellationToken ct = default) =>
+        await repository.GetByIdAsync(id, ct);
+
+    public async Task<IEnumerable<Contract>> GetByClientIdAsync(int clientId, CancellationToken ct = default) =>
+        await repository.GetByClientIdAsync(clientId, ct);
+
+    public async Task<IEnumerable<Contract>> GetActiveContractsAsync(CancellationToken ct = default) =>
+        await repository.GetActiveContractsAsync(ct);
+
+    public async Task<IEnumerable<Contract>> GetExpiringContractsAsync(int daysAhead = 30, CancellationToken ct = default) =>
+        await repository.GetExpiringContractsAsync(daysAhead, ct);
+
+    public async Task<decimal> GetMonthlyRecurringRevenueAsync(CancellationToken ct = default) =>
+        await repository.GetMonthlyRecurringRevenueAsync(ct);
+}
diff --git a/TaxBaik.Application/Services/RevenueTrackingService.cs b/TaxBaik.Application/Services/RevenueTrackingService.cs
new file mode 100644
index 0000000..d9a3b2e
--- /dev/null
+++ b/TaxBaik.Application/Services/RevenueTrackingService.cs
@@ -0,0 +1,52 @@
+namespace TaxBaik.Application.Services;
+
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class RevenueTrackingService(IRevenueTrackingRepository repository)
+{
+    public async Task<int> CreateAsync(int clientId, string invoiceNumber, DateTime invoiceDate,
+        decimal amount, string? serviceType = null, DateTime? dueDate = null, CancellationToken ct = default)
+    {
+        if (clientId <= 0)
+            throw new ValidationException("유효한 고객을 선택하세요.");
+        if (string.IsNullOrWhiteSpace(invoiceNumber))
+            throw new ValidationException("인보이스 번호를 입력하세요.");
+        if (amount <= 0)
+            throw new ValidationException("금액은 0보다 커야 합니다.");
+
+        var revenue = new RevenueTracking
+        {
+            ClientId = clientId,
+            InvoiceNumber = invoiceNumber.Trim(),
+            InvoiceDate = invoiceDate,
+            Amount = amount,
+            ServiceType = string.IsNullOrWhiteSpace(serviceType) ? null : serviceType.Trim(),
+            DueDate = dueDate,
+            PaymentStatus = "pending",
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        return await repository.CreateAsync(revenue, ct);
+    }
+
+    public async Task<IEnumerable<RevenueTracking>> GetByClientIdAsync(int clientId, CancellationToken ct = default) =>
+        await repository.GetByClientIdAsync(clientId, ct);
+
+    public async Task<IEnumerable<RevenueTracking>> GetPendingPaymentsAsync(CancellationToken ct = default) =>
+        await repository.GetPendingPaymentsAsync(ct);
+
+    public async Task<IEnumerable<RevenueTracking>> GetMonthlyRevenueAsync(DateTime month, CancellationToken ct = default)
+    {
+        var startDate = new DateTime(month.Year, month.Month, 1);
+        var endDate = startDate.AddMonths(1).AddDays(-1);
+        return await repository.GetByDateRangeAsync(startDate, endDate, ct);
+    }
+
+    public async Task MarkPaidAsync(int id, DateTime paymentDate, CancellationToken ct = default) =>
+        await repository.MarkPaidAsync(id, paymentDate, ct);
+
+    public async Task<decimal> GetTotalRevenueAsync(DateTime startDate, DateTime endDate, CancellationToken ct = default) =>
+        await repository.GetTotalRevenueAsync(startDate, endDate, ct);
+}
diff --git a/TaxBaik.Application/Services/TaxFilingScheduleService.cs b/TaxBaik.Application/Services/TaxFilingScheduleService.cs
new file mode 100644
index 0000000..fcf1dbd
--- /dev/null
+++ b/TaxBaik.Application/Services/TaxFilingScheduleService.cs
@@ -0,0 +1,50 @@
+namespace TaxBaik.Application.Services;
+
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class TaxFilingScheduleService(ITaxFilingScheduleRepository repository)
+{
+    public async Task<int> CreateAsync(int clientId, string filingType, DateTime dueDate, int filingYear,
+        int? assignedToId = null, CancellationToken ct = default)
+    {
+        if (clientId <= 0)
+            throw new ValidationException("유효한 고객을 선택하세요.");
+        if (string.IsNullOrWhiteSpace(filingType))
+            throw new ValidationException("신고 유형을 입력하세요.");
+        if (dueDate < DateTime.Today)
+            throw new ValidationException("마감일은 오늘 이후여야 합니다.");
+
+        var schedule = new TaxFilingSchedule
+        {
+            ClientId = clientId,
+            FilingType = filingType.Trim(),
+            DueDate = dueDate,
+            FilingYear = filingYear,
+            Status = "pending",
+            AssignedToId = assignedToId,
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        return await repository.CreateAsync(schedule, ct);
+    }
+
+    public async Task<TaxFilingSchedule?> GetByIdAsync(int id, CancellationToken ct = default) =>
+        await repository.GetByIdAsync(id, ct);
+
+    public async Task<IEnumerable<TaxFilingSchedule>> GetByClientIdAsync(int clientId, CancellationToken ct = default) =>
+        await repository.GetByClientIdAsync(clientId, ct);
+
+    public async Task<IEnumerable<TaxFilingSchedule>> GetUpcomingDuesAsync(int daysAhead = 30, CancellationToken ct = default) =>
+        await repository.GetUpcomingDuesAsync(daysAhead, ct);
+
+    public async Task MarkCompletedAsync(int id, CancellationToken ct = default) =>
+        await repository.MarkCompletedAsync(id, ct);
+
+    public async Task<int> GetPendingCountAsync(CancellationToken ct = default)
+    {
+        var pending = await repository.GetByStatusAsync("pending", ct);
+        return pending.Count();
+    }
+}
diff --git a/TaxBaik.Application/Services/TaxProfileService.cs b/TaxBaik.Application/Services/TaxProfileService.cs
new file mode 100644
index 0000000..7dfe1d4
--- /dev/null
+++ b/TaxBaik.Application/Services/TaxProfileService.cs
@@ -0,0 +1,58 @@
+namespace TaxBaik.Application.Services;
+
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class TaxProfileService(ITaxProfileRepository repository)
+{
+    public async Task<int> CreateAsync(int clientId, string? businessType, string? businessRegistration = null,
+        string? accountingMethod = null, DateTime? establishmentDate = null, CancellationToken ct = default)
+    {
+        if (clientId <= 0)
+            throw new ValidationException("유효한 고객을 선택하세요.");
+        if (string.IsNullOrWhiteSpace(businessType))
+            throw new ValidationException("사업 유형을 입력하세요.");
+
+        var profile = new TaxProfile
+        {
+            ClientId = clientId,
+            BusinessType = businessType.Trim(),
+            BusinessRegistration = string.IsNullOrWhiteSpace(businessRegistration) ? null : businessRegistration.Trim(),
+            EstablishmentDate = establishmentDate,
+            AccountingMethod = string.IsNullOrWhiteSpace(accountingMethod) ? null : accountingMethod.Trim(),
+            TaxRiskLevel = "normal",
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        return await repository.CreateAsync(profile, ct);
+    }
+
+    public async Task<TaxProfile?> GetByClientIdAsync(int clientId, CancellationToken ct = default) =>
+        await repository.GetByClientIdAsync(clientId, ct);
+
+    public async Task UpdateAsync(int profileId, string? businessType, string? accountingMethod,
+        DateTime? nextFilingDueDate, string taxRiskLevel = "normal", CancellationToken ct = default)
+    {
+        var profile = new TaxProfile { Id = profileId };
+        if (!string.IsNullOrWhiteSpace(businessType))
+            profile.BusinessType = businessType.Trim();
+        if (!string.IsNullOrWhiteSpace(accountingMethod))
+            profile.AccountingMethod = accountingMethod.Trim();
+        profile.NextFilingDueDate = nextFilingDueDate;
+        profile.TaxRiskLevel = taxRiskLevel;
+        profile.UpdatedAt = DateTime.UtcNow;
+
+        await repository.UpdateAsync(profile, ct);
+    }
+
+    public async Task<IEnumerable<TaxProfile>> GetHighRiskProfilesAsync(CancellationToken ct = default) =>
+        await repository.GetByRiskLevelAsync("high", ct);
+
+    public async Task<IEnumerable<TaxProfile>> GetUpcomingFilingDuesAsync(int daysAhead = 30, CancellationToken ct = default)
+    {
+        var startDate = DateTime.Today;
+        var endDate = startDate.AddDays(daysAhead);
+        return await repository.GetUpcomingFilingDuesAsync(startDate, endDate, ct);
+    }
+}
diff --git a/TaxBaik.Infrastructure/DependencyInjection.cs b/TaxBaik.Infrastructure/DependencyInjection.cs
index 9c99c09..19610c1 100644
--- a/TaxBaik.Infrastructure/DependencyInjection.cs
+++ b/TaxBaik.Infrastructure/DependencyInjection.cs
@@ -21,6 +21,11 @@ public static class DependencyInjection
         services.AddScoped<IConsultationRepository, ConsultationRepository>();
         services.AddScoped<ITaxFilingRepository, TaxFilingRepository>();
         services.AddScoped<ICompanyRepository, CompanyRepository>();
+        services.AddScoped<ITaxProfileRepository, TaxProfileRepository>();
+        services.AddScoped<ITaxFilingScheduleRepository, TaxFilingScheduleRepository>();
+        services.AddScoped<IConsultingActivityRepository, ConsultingActivityRepository>();
+        services.AddScoped<IContractRepository, ContractRepository>();
+        services.AddScoped<IRevenueTrackingRepository, RevenueTrackingRepository>();
 
         return services;
     }
diff --git a/TaxBaik.Infrastructure/Repositories/ConsultingActivityRepository.cs b/TaxBaik.Infrastructure/Repositories/ConsultingActivityRepository.cs
new file mode 100644
index 0000000..0883e19
--- /dev/null
+++ b/TaxBaik.Infrastructure/Repositories/ConsultingActivityRepository.cs
@@ -0,0 +1,57 @@
+namespace TaxBaik.Infrastructure.Repositories;
+
+using Dapper;
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class ConsultingActivityRepository(IDbConnectionFactory connectionFactory) : BaseRepository(connectionFactory), IConsultingActivityRepository
+{
+    public async Task<int> CreateAsync(ConsultingActivity activity, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstAsync<int>(
+            @"INSERT INTO consulting_activities (client_id, activity_type, activity_date, activity_time, assigned_consultant, description, outcome, next_followup_date, notes, created_at, updated_at)
+              VALUES (@ClientId, @ActivityType, @ActivityDate, @ActivityTime, @AssignedConsultantId, @Description, @Outcome, @NextFollowupDate, @Notes, NOW(), NOW())
+              RETURNING id",
+            activity);
+    }
+
+    public async Task<IEnumerable<ConsultingActivity>> GetByClientIdAsync(int clientId, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<ConsultingActivity>(
+            @"SELECT id, client_id, activity_type, activity_date, activity_time, assigned_consultant, description, outcome, next_followup_date, notes, created_at, updated_at
+              FROM consulting_activities WHERE client_id = @ClientId ORDER BY activity_date DESC",
+            new { ClientId = clientId });
+    }
+
+    public async Task<IEnumerable<ConsultingActivity>> GetPendingFollowupsAsync(CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<ConsultingActivity>(
+            @"SELECT id, client_id, activity_type, activity_date, activity_time, assigned_consultant, description, outcome, next_followup_date, notes, created_at, updated_at
+              FROM consulting_activities WHERE next_followup_date IS NOT NULL AND next_followup_date <= CURRENT_DATE
+              ORDER BY next_followup_date ASC");
+    }
+
+    public async Task<IEnumerable<ConsultingActivity>> GetByConsultantAsync(int consultantId, DateTime fromDate, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<ConsultingActivity>(
+            @"SELECT id, client_id, activity_type, activity_date, activity_time, assigned_consultant, description, outcome, next_followup_date, notes, created_at, updated_at
+              FROM consulting_activities WHERE assigned_consultant = @ConsultantId AND activity_date >= @FromDate
+              ORDER BY activity_date DESC",
+            new { ConsultantId = consultantId, FromDate = fromDate });
+    }
+
+    public async Task UpdateAsync(ConsultingActivity activity, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE consulting_activities SET activity_type = @ActivityType, activity_date = @ActivityDate,
+              activity_time = @ActivityTime, assigned_consultant = @AssignedConsultantId, description = @Description,
+              outcome = @Outcome, next_followup_date = @NextFollowupDate, notes = @Notes, updated_at = NOW()
+              WHERE id = @Id",
+            activity);
+    }
+}
diff --git a/TaxBaik.Infrastructure/Repositories/ContractRepository.cs b/TaxBaik.Infrastructure/Repositories/ContractRepository.cs
new file mode 100644
index 0000000..e68f535
--- /dev/null
+++ b/TaxBaik.Infrastructure/Repositories/ContractRepository.cs
@@ -0,0 +1,74 @@
+namespace TaxBaik.Infrastructure.Repositories;
+
+using Dapper;
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class ContractRepository(IDbConnectionFactory connectionFactory) : BaseRepository(connectionFactory), IContractRepository
+{
+    public async Task<int> CreateAsync(Contract contract, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstAsync<int>(
+            @"INSERT INTO contracts (client_id, contract_number, service_type, contract_date, start_date, end_date, monthly_fee, total_amount, payment_status, status, notes, created_at, updated_at)
+              VALUES (@ClientId, @ContractNumber, @ServiceType, @ContractDate, @StartDate, @EndDate, @MonthlyFee, @TotalAmount, @PaymentStatus, @Status, @Notes, NOW(), NOW())
+              RETURNING id",
+            contract);
+    }
+
+    public async Task<Contract?> GetByIdAsync(int id, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstOrDefaultAsync<Contract>(
+            @"SELECT id, client_id, contract_number, service_type, contract_date, start_date, end_date, monthly_fee, total_amount, payment_status, status, notes, created_at, updated_at
+              FROM contracts WHERE id = @Id",
+            new { Id = id });
+    }
+
+    public async Task<IEnumerable<Contract>> GetByClientIdAsync(int clientId, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<Contract>(
+            @"SELECT id, client_id, contract_number, service_type, contract_date, start_date, end_date, monthly_fee, total_amount, payment_status, status, notes, created_at, updated_at
+              FROM contracts WHERE client_id = @ClientId ORDER BY contract_date DESC",
+            new { ClientId = clientId });
+    }
+
+    public async Task<IEnumerable<Contract>> GetActiveContractsAsync(CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<Contract>(
+            @"SELECT id, client_id, contract_number, service_type, contract_date, start_date, end_date, monthly_fee, total_amount, payment_status, status, notes, created_at, updated_at
+              FROM contracts WHERE status = 'active' ORDER BY client_id");
+    }
+
+    public async Task<IEnumerable<Contract>> GetExpiringContractsAsync(int daysAhead = 30, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<Contract>(
+            @"SELECT id, client_id, contract_number, service_type, contract_date, start_date, end_date, monthly_fee, total_amount, payment_status, status, notes, created_at, updated_at
+              FROM contracts
+              WHERE status = 'active' AND end_date IS NOT NULL AND end_date BETWEEN CURRENT_DATE AND CURRENT_DATE + INTERVAL '1 day' * @DaysAhead
+              ORDER BY end_date ASC",
+            new { DaysAhead = daysAhead });
+    }
+
+    public async Task UpdateAsync(Contract contract, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE contracts SET contract_number = @ContractNumber, service_type = @ServiceType, contract_date = @ContractDate,
+              start_date = @StartDate, end_date = @EndDate, monthly_fee = @MonthlyFee, total_amount = @TotalAmount,
+              payment_status = @PaymentStatus, status = @Status, notes = @Notes, updated_at = NOW()
+              WHERE id = @Id",
+            contract);
+    }
+
+    public async Task<decimal> GetMonthlyRecurringRevenueAsync(CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        var result = await conn.QueryFirstAsync<decimal>(
+            @"SELECT COALESCE(SUM(monthly_fee), 0) FROM contracts WHERE status = 'active' AND monthly_fee IS NOT NULL");
+        return result;
+    }
+}
diff --git a/TaxBaik.Infrastructure/Repositories/RevenueTrackingRepository.cs b/TaxBaik.Infrastructure/Repositories/RevenueTrackingRepository.cs
new file mode 100644
index 0000000..8a527a9
--- /dev/null
+++ b/TaxBaik.Infrastructure/Repositories/RevenueTrackingRepository.cs
@@ -0,0 +1,72 @@
+namespace TaxBaik.Infrastructure.Repositories;
+
+using Dapper;
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class RevenueTrackingRepository(IDbConnectionFactory connectionFactory) : BaseRepository(connectionFactory), IRevenueTrackingRepository
+{
+    public async Task<int> CreateAsync(RevenueTracking revenue, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstAsync<int>(
+            @"INSERT INTO revenue_tracking (client_id, invoice_number, invoice_date, service_type, amount, payment_status, payment_date, due_date, notes, created_at, updated_at)
+              VALUES (@ClientId, @InvoiceNumber, @InvoiceDate, @ServiceType, @Amount, @PaymentStatus, @PaymentDate, @DueDate, @Notes, NOW(), NOW())
+              RETURNING id",
+            revenue);
+    }
+
+    public async Task<IEnumerable<RevenueTracking>> GetByClientIdAsync(int clientId, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<RevenueTracking>(
+            @"SELECT id, client_id, invoice_number, invoice_date, service_type, amount, payment_status, payment_date, due_date, notes, created_at, updated_at
+              FROM revenue_tracking WHERE client_id = @ClientId ORDER BY invoice_date DESC",
+            new { ClientId = clientId });
+    }
+
+    public async Task<IEnumerable<RevenueTracking>> GetPendingPaymentsAsync(CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<RevenueTracking>(
+            @"SELECT id, client_id, invoice_number, invoice_date, service_type, amount, payment_status, payment_date, due_date, notes, created_at, updated_at
+              FROM revenue_tracking WHERE payment_status = 'pending' ORDER BY due_date ASC");
+    }
+
+    public async Task<IEnumerable<RevenueTracking>> GetByDateRangeAsync(DateTime startDate, DateTime endDate, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<RevenueTracking>(
+            @"SELECT id, client_id, invoice_number, invoice_date, service_type, amount, payment_status, payment_date, due_date, notes, created_at, updated_at
+              FROM revenue_tracking WHERE invoice_date BETWEEN @StartDate AND @EndDate ORDER BY invoice_date DESC",
+            new { StartDate = startDate, EndDate = endDate });
+    }
+
+    public async Task UpdateAsync(RevenueTracking revenue, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE revenue_tracking SET invoice_number = @InvoiceNumber, invoice_date = @InvoiceDate,
+              service_type = @ServiceType, amount = @Amount, payment_status = @PaymentStatus,
+              payment_date = @PaymentDate, due_date = @DueDate, notes = @Notes, updated_at = NOW()
+              WHERE id = @Id",
+            revenue);
+    }
+
+    public async Task MarkPaidAsync(int id, DateTime paymentDate, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE revenue_tracking SET payment_status = 'paid', payment_date = @PaymentDate, updated_at = NOW() WHERE id = @Id",
+            new { Id = id, PaymentDate = paymentDate });
+    }
+
+    public async Task<decimal> GetTotalRevenueAsync(DateTime startDate, DateTime endDate, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        var result = await conn.QueryFirstAsync<decimal>(
+            @"SELECT COALESCE(SUM(amount), 0) FROM revenue_tracking WHERE invoice_date BETWEEN @StartDate AND @EndDate",
+            new { StartDate = startDate, EndDate = endDate });
+        return result;
+    }
+}
diff --git a/TaxBaik.Infrastructure/Repositories/TaxFilingScheduleRepository.cs b/TaxBaik.Infrastructure/Repositories/TaxFilingScheduleRepository.cs
new file mode 100644
index 0000000..6c2c4ab
--- /dev/null
+++ b/TaxBaik.Infrastructure/Repositories/TaxFilingScheduleRepository.cs
@@ -0,0 +1,73 @@
+namespace TaxBaik.Infrastructure.Repositories;
+
+using Dapper;
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class TaxFilingScheduleRepository(IDbConnectionFactory connectionFactory) : BaseRepository(connectionFactory), ITaxFilingScheduleRepository
+{
+    public async Task<int> CreateAsync(TaxFilingSchedule schedule, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstAsync<int>(
+            @"INSERT INTO tax_filing_schedules (client_id, filing_type, due_date, filing_year, status, assigned_to, notes, created_at, updated_at)
+              VALUES (@ClientId, @FilingType, @DueDate, @FilingYear, @Status, @AssignedToId, @Notes, NOW(), NOW())
+              RETURNING id",
+            schedule);
+    }
+
+    public async Task<TaxFilingSchedule?> GetByIdAsync(int id, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstOrDefaultAsync<TaxFilingSchedule>(
+            @"SELECT id, client_id, filing_type, due_date, filing_year, status, assigned_to, completed_date, notes, created_at, updated_at
+              FROM tax_filing_schedules WHERE id = @Id",
+            new { Id = id });
+    }
+
+    public async Task<IEnumerable<TaxFilingSchedule>> GetByClientIdAsync(int clientId, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<TaxFilingSchedule>(
+            @"SELECT id, client_id, filing_type, due_date, filing_year, status, assigned_to, completed_date, notes, created_at, updated_at
+              FROM tax_filing_schedules WHERE client_id = @ClientId ORDER BY due_date DESC",
+            new { ClientId = clientId });
+    }
+
+    public async Task<IEnumerable<TaxFilingSchedule>> GetUpcomingDuesAsync(int daysAhead = 30, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<TaxFilingSchedule>(
+            @"SELECT id, client_id, filing_type, due_date, filing_year, status, assigned_to, completed_date, notes, created_at, updated_at
+              FROM tax_filing_schedules
+              WHERE status = 'pending' AND due_date BETWEEN CURRENT_DATE AND CURRENT_DATE + INTERVAL '1 day' * @DaysAhead
+              ORDER BY due_date ASC",
+            new { DaysAhead = daysAhead });
+    }
+
+    public async Task<IEnumerable<TaxFilingSchedule>> GetByStatusAsync(string status, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<TaxFilingSchedule>(
+            @"SELECT id, client_id, filing_type, due_date, filing_year, status, assigned_to, completed_date, notes, created_at, updated_at
+              FROM tax_filing_schedules WHERE status = @Status ORDER BY due_date",
+            new { Status = status });
+    }
+
+    public async Task UpdateAsync(TaxFilingSchedule schedule, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE tax_filing_schedules SET filing_type = @FilingType, due_date = @DueDate, status = @Status,
+              assigned_to = @AssignedToId, notes = @Notes, updated_at = NOW() WHERE id = @Id",
+            schedule);
+    }
+
+    public async Task MarkCompletedAsync(int id, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE tax_filing_schedules SET status = 'completed', completed_date = NOW(), updated_at = NOW() WHERE id = @Id",
+            new { Id = id });
+    }
+}
diff --git a/TaxBaik.Infrastructure/Repositories/TaxProfileRepository.cs b/TaxBaik.Infrastructure/Repositories/TaxProfileRepository.cs
new file mode 100644
index 0000000..f1eedc2
--- /dev/null
+++ b/TaxBaik.Infrastructure/Repositories/TaxProfileRepository.cs
@@ -0,0 +1,70 @@
+namespace TaxBaik.Infrastructure.Repositories;
+
+using Dapper;
+using TaxBaik.Domain.Entities;
+using TaxBaik.Domain.Interfaces;
+
+public class TaxProfileRepository(IDbConnectionFactory connectionFactory) : BaseRepository(connectionFactory), ITaxProfileRepository
+{
+    public async Task<int> CreateAsync(TaxProfile profile, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstAsync<int>(
+            @"INSERT INTO tax_profiles (client_id, business_registration, business_type, establishment_date,
+              annual_revenue_range, employee_count, accounting_method, fiscal_year_end, last_filing_date,
+              next_filing_due_date, tax_risk_level, previous_audit_history, special_notes, created_at, updated_at)
+              VALUES (@ClientId, @BusinessRegistration, @BusinessType, @EstablishmentDate, @AnnualRevenueRange,
+              @EmployeeCount, @AccountingMethod, @FiscalYearEnd, @LastFilingDate, @NextFilingDueDate,
+              @TaxRiskLevel, @PreviousAuditHistory, @SpecialNotes, NOW(), NOW())
+              RETURNING id",
+            profile);
+    }
+
+    public async Task<TaxProfile?> GetByClientIdAsync(int clientId, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryFirstOrDefaultAsync<TaxProfile>(
+            @"SELECT id, client_id, business_registration, business_type, establishment_date,
+              annual_revenue_range, employee_count, accounting_method, fiscal_year_end, last_filing_date,
+              next_filing_due_date, tax_risk_level, previous_audit_history, special_notes, created_at, updated_at
+              FROM tax_profiles WHERE client_id = @ClientId",
+            new { ClientId = clientId });
+    }
+
+    public async Task UpdateAsync(TaxProfile profile, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        await conn.ExecuteAsync(
+            @"UPDATE tax_profiles SET business_registration = @BusinessRegistration, business_type = @BusinessType,
+              establishment_date = @EstablishmentDate, annual_revenue_range = @AnnualRevenueRange,
+              employee_count = @EmployeeCount, accounting_method = @AccountingMethod, fiscal_year_end = @FiscalYearEnd,
+              last_filing_date = @LastFilingDate, next_filing_due_date = @NextFilingDueDate,
+              tax_risk_level = @TaxRiskLevel, previous_audit_history = @PreviousAuditHistory,
+              special_notes = @SpecialNotes, updated_at = NOW()
+              WHERE id = @Id",
+            profile);
+    }
+
+    public async Task<IEnumerable<TaxProfile>> GetByRiskLevelAsync(string riskLevel, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<TaxProfile>(
+            @"SELECT id, client_id, business_registration, business_type, establishment_date,
+              annual_revenue_range, employee_count, accounting_method, fiscal_year_end, last_filing_date,
+              next_filing_due_date, tax_risk_level, previous_audit_history, special_notes, created_at, updated_at
+              FROM tax_profiles WHERE tax_risk_level = @RiskLevel ORDER BY client_id",
+            new { RiskLevel = riskLevel });
+    }
+
+    public async Task<IEnumerable<TaxProfile>> GetUpcomingFilingDuesAsync(DateTime startDate, DateTime endDate, CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<TaxProfile>(
+            @"SELECT id, client_id, business_registration, business_type, establishment_date,
+              annual_revenue_range, employee_count, accounting_method, fiscal_year_end, last_filing_date,
+              next_filing_due_date, tax_risk_level, previous_audit_history, special_notes, created_at, updated_at
+              FROM tax_profiles WHERE next_filing_due_date BETWEEN @StartDate AND @EndDate
+              ORDER BY next_filing_due_date",
+            new { StartDate = startDate, EndDate = endDate });
+    }
+}
diff --git a/TaxBaik.Web/Controllers/TaxProfileController.cs b/TaxBaik.Web/Controllers/TaxProfileController.cs
new file mode 100644
index 0000000..d285356
--- /dev/null
+++ b/TaxBaik.Web/Controllers/TaxProfileController.cs
@@ -0,0 +1,97 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using TaxBaik.Application.Services;
+
+namespace TaxBaik.Web.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+[Authorize]
+public class TaxProfileController(TaxProfileService taxProfileService) : ControllerBase
+{
+    [HttpPost]
+    public async Task<IActionResult> Create([FromBody] CreateTaxProfileRequest request)
+    {
+        try
+        {
+            var id = await taxProfileService.CreateAsync(request.ClientId, request.BusinessType,
+                request.BusinessRegistration, request.AccountingMethod, request.EstablishmentDate);
+            return CreatedAtAction(nameof(GetByClientId), new { clientId = request.ClientId }, new { id });
+        }
+        catch (ValidationException ex)
+        {
+            return BadRequest(new { error = ex.Message });
+        }
+    }
+
+    [HttpGet("client/{clientId:int}")]
+    public async Task<IActionResult> GetByClientId(int clientId)
+    {
+        try
+        {
+            var profile = await taxProfileService.GetByClientIdAsync(clientId);
+            if (profile == null)
+                return NotFound(new { error = "세무 프로필을 찾을 수 없습니다." });
+            return Ok(profile);
+        }
+        catch (Exception ex)
+        {
+            return StatusCode(500, new { error = "조회 실패", message = ex.Message });
+        }
+    }
+
+    [HttpGet("high-risk")]
+    public async Task<IActionResult> GetHighRiskProfiles()
+    {
+        try
+        {
+            var profiles = await taxProfileService.GetHighRiskProfilesAsync();
+            return Ok(new { data = profiles });
+        }
+        catch (Exception ex)
+        {
+            return StatusCode(500, new { error = "조회 실패", message = ex.Message });
+        }
+    }
+
+    [HttpGet("upcoming-filings")]
+    public async Task<IActionResult> GetUpcomingFiliings([FromQuery] int daysAhead = 30)
+    {
+        try
+        {
+            var profiles = await taxProfileService.GetUpcomingFilingDuesAsync(daysAhead);
+            return Ok(new { data = profiles, daysAhead });
+        }
+        catch (Exception ex)
+        {
+            return StatusCode(500, new { error = "조회 실패", message = ex.Message });
+        }
+    }
+
+    [HttpPut("{id:int}")]
+    public async Task<IActionResult> Update(int id, [FromBody] UpdateTaxProfileRequest request)
+    {
+        try
+        {
+            await taxProfileService.UpdateAsync(id, request.BusinessType, request.AccountingMethod,
+                request.NextFilingDueDate, request.TaxRiskLevel);
+            return Ok(new { message = "세무 프로필이 수정되었습니다." });
+        }
+        catch (ValidationException ex)
+        {
+            return BadRequest(new { error = ex.Message });
+        }
+        catch (Exception ex)
+        {
+            return StatusCode(500, new { error = "수정 실패", message = ex.Message });
+        }
+    }
+
+    public record CreateTaxProfileRequest(
+        int ClientId, string BusinessType, string? BusinessRegistration = null,
+        string? AccountingMethod = null, DateTime? EstablishmentDate = null);
+
+    public record UpdateTaxProfileRequest(
+        string? BusinessType = null, string? AccountingMethod = null,
+        DateTime? NextFilingDueDate = null, string TaxRiskLevel = "normal");
+}