diff --git a/tests/Application.Tests.Integration/Borrows/Commands/ApproveBorrowRequestTests.cs b/tests/Application.Tests.Integration/Borrows/Commands/ApproveBorrowRequestTests.cs
new file mode 100644
index 00000000..87a40fd6
--- /dev/null
+++ b/tests/Application.Tests.Integration/Borrows/Commands/ApproveBorrowRequestTests.cs
@@ -0,0 +1,168 @@
+using Application.Borrows.Commands;
+using Application.Common.Exceptions;
+using Application.Identity;
+using Domain.Entities.Physical;
+using Domain.Statuses;
+using FluentAssertions;
+using Infrastructure.Persistence;
+using Microsoft.Extensions.DependencyInjection;
+using NodaTime;
+using Xunit;
+
+namespace Application.Tests.Integration.Borrows.Commands;
+
+public class ApproveBorrowRequestTests : BaseClassFixture
+{
+    public ApproveBorrowRequestTests(CustomApiFactory apiFactory) : base(apiFactory)
+    {
+        
+    }
+
+    [Fact]
+    public async Task ShouldApproveRequest_WhenRequestIsValid()
+    {
+        // Arrange
+        var document = CreateNDocuments(1).First();
+
+        var user = CreateUser(IdentityData.Roles.Employee, "abcdef");
+
+        var request = CreateBorrowRequest(user, document, BorrowRequestStatus.Pending);
+
+        await AddAsync(request);
+        
+        var command = new ApproveBorrowRequest.Command()
+        {
+            BorrowId = request.Id,
+        };
+        
+        // Act
+        var result = await SendAsync(command);
+        
+        // Assert 
+        result.Status.Should().Be(BorrowRequestStatus.Approved.ToString());
+        
+        // Cleanup
+        Remove(request);
+        Remove(user);
+        Remove(document);
+    }
+
+    [Fact]
+    public async Task ShouldThrowKeyNotFoundException_WhenRequestDoesNotExist()
+    {
+        // Arrange
+        var command = new ApproveBorrowRequest.Command()
+        {
+            BorrowId = Guid.NewGuid(),
+        };
+        
+        // Act
+        var result = async () => await SendAsync(command);
+
+        // Assert
+        await result.Should().ThrowAsync<KeyNotFoundException>()
+            .WithMessage("Borrow request does not exist.");
+    }
+
+    [Fact]
+    public async Task ShouldThrowConflictException_WhenDocumentIsLost()
+    {
+        // Arrange
+        var document = CreateNDocuments(1).First();
+
+        document.Status = DocumentStatus.Lost;
+
+        var user = CreateUser(IdentityData.Roles.Employee, "abcdef");
+
+        var request = CreateBorrowRequest(user, document, BorrowRequestStatus.Pending);
+
+        await AddAsync(request);
+        
+        var command = new ApproveBorrowRequest.Command()
+        {
+            BorrowId = request.Id,
+        };
+        
+        // Act
+        var result = async () => await SendAsync(command);
+        
+        // Assert
+        await result.Should().ThrowAsync<ConflictException>()
+            .WithMessage("Document is lost. Request is unprocessable.");
+        (await FindAsync<Borrow>(request.Id))!.Status.Should().Be(BorrowRequestStatus.NotProcessable);
+
+        // Cleanup
+        Remove(request);
+        Remove(user);
+        Remove(document);
+    }
+
+    [Fact]
+    public async Task ShouldThrowConflictException_WhenRequestStatusIsNotPendingAndRejected()
+    {
+        var document = CreateNDocuments(1).First();
+
+        var user = CreateUser(IdentityData.Roles.Employee, "abcdef");
+
+        var request = CreateBorrowRequest(user, document, BorrowRequestStatus.CheckedOut);
+
+        await AddAsync(request);
+        
+        var command = new ApproveBorrowRequest.Command()
+        {
+            BorrowId = request.Id,
+        };
+        
+        // Act
+        var result = async () => await SendAsync(command);
+        
+        // Assert
+        await result.Should().ThrowAsync<ConflictException>()
+            .WithMessage("Request cannot be approved.");
+        
+        // Cleanup
+        Remove(request);
+        Remove(user);
+        Remove(document);
+    }
+
+    [Fact]
+    public async Task ShouldThrowConflictException_WhenRequestTimespanOverlapAnApprovedOrCheckedOutRequestTimespan()
+    {
+        using var scope = ScopeFactory.CreateScope();
+        var context = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();
+        var document = CreateNDocuments(1).First();
+
+        var user1 = CreateUser(IdentityData.Roles.Employee, "abcdef");
+        var user2 = CreateUser(IdentityData.Roles.Employee, "aaaaaa");
+
+        var request1 = CreateBorrowRequest(user1, document, BorrowRequestStatus.Approved);
+        
+        var request2 = CreateBorrowRequest(user2, document, BorrowRequestStatus.Pending);
+        request2.BorrowTime = request2.BorrowTime.Plus(Period.FromMinutes(30));
+        request2.DueTime = request2.DueTime.Plus(Period.FromHours(1));
+        
+        await context.AddAsync(request1);
+        await context.AddAsync(request2);
+        await context.SaveChangesAsync();
+        
+        var command = new ApproveBorrowRequest.Command()
+        {
+            BorrowId = request2.Id,
+        };
+        
+        // Act
+        var result = async () => await SendAsync(command);
+        
+        // Assert
+        await result.Should().ThrowAsync<ConflictException>()
+            .WithMessage("This document cannot be borrowed.");
+        
+        // Cleanup
+        Remove(request1);
+        Remove(request2);
+        Remove(user1);
+        Remove(user2);
+        Remove(document);
+    }
+}
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