diff --git a/DocumentOperator.API/Controllers/PdfAttachmentController.cs b/DocumentOperator.API/Controllers/PdfAttachmentController.cs
index a3f4324..a6d31af 100644
--- a/DocumentOperator.API/Controllers/PdfAttachmentController.cs
+++ b/DocumentOperator.API/Controllers/PdfAttachmentController.cs
@@ -1,5 +1,6 @@
 using DocumentOperator.Application.CheckPdfAttachments.Queries;
 using DocumentOperator.Application.Common.DTOs;
+using DocumentOperator.Domain.Common.Exceptions;
 using MediatR;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
@@ -33,13 +34,11 @@ public class PdfAttachmentController(IMediator mediator) : ControllerBase
         IFormFile file,
         CancellationToken cancellationToken)
     {
-        // Convert IFormFile to byte array
-        using var memoryStream = new MemoryStream();
-        await file.CopyToAsync(memoryStream, cancellationToken);
-        byte[] pdfBytes = memoryStream.ToArray();
+        // Use IFormFile stream directly (no intermediate byte[] conversion)
+        using var pdfStream = file.OpenReadStream();
 
         // Send query to MediatR (ValidationBehavior runs automatically)
-        var query = new CheckPdfAttachmentsQuery { PdfBytes = pdfBytes };
+        var query = new CheckPdfAttachmentsQuery { PdfStream = pdfStream };
         var result = await mediator.Send(query, cancellationToken);
 
         return Ok(result);
@@ -64,8 +63,21 @@ public class PdfAttachmentController(IMediator mediator) : ControllerBase
         [FromBody] CheckPdfAttachmentsRequest request,
         CancellationToken cancellationToken)
     {
+        // Convert Base64 to stream (wrap in try-catch to throw BadRequestException)
+        byte[] pdfBytes;
+        try
+        {
+            pdfBytes = Convert.FromBase64String(request.Base64Pdf);
+        }
+        catch (FormatException ex)
+        {
+            throw new BadRequestException("Invalid Base64 format: " + ex.Message);
+        }
+        
+        using var pdfStream = new MemoryStream(pdfBytes);
+        
         // Send query to MediatR (ValidationBehavior runs automatically)
-        var query = new CheckPdfAttachmentsQuery { Base64Pdf = request.Base64Pdf };
+        var query = new CheckPdfAttachmentsQuery { PdfStream = pdfStream };
         var result = await mediator.Send(query, cancellationToken);
 
         return Ok(result);
diff --git a/DocumentOperator.API/Controllers/PdfValidationController.cs b/DocumentOperator.API/Controllers/PdfValidationController.cs
index b6a63cc..66f6428 100644
--- a/DocumentOperator.API/Controllers/PdfValidationController.cs
+++ b/DocumentOperator.API/Controllers/PdfValidationController.cs
@@ -1,6 +1,7 @@
 using DocumentOperator.Application.Common.DTOs;
 using DocumentOperator.Application.ValidatePdf.Queries;
 using DocumentOperator.Application.ValidatePdfA.Queries;
+using DocumentOperator.Domain.Common.Exceptions;
 using MediatR;
 using Microsoft.AspNetCore.Mvc;
 
@@ -42,13 +43,11 @@ public class PdfValidationController(IMediator Mediator) : ControllerBase
             });
         }
 
-        // Convert IFormFile to byte array
-        using var memoryStream = new MemoryStream();
-        await file.CopyToAsync(memoryStream, cancellationToken);
-        byte[] pdfBytes = memoryStream.ToArray();
-
+        // Use IFormFile stream directly (no intermediate byte[] conversion)
+        using var pdfStream = file.OpenReadStream();
+        
         // Direct pass-through to MediatR
-        var query = new ValidatePdfQuery { PdfBytes = pdfBytes };
+        var query = new ValidatePdfQuery { PdfStream = pdfStream };
         var result = await Mediator.Send(query, cancellationToken);
         
         return Ok(result);
@@ -57,7 +56,7 @@ public class PdfValidationController(IMediator Mediator) : ControllerBase
     /// <summary>
     /// Validates a PDF document and returns metadata (Base64 JSON)
     /// </summary>
-    /// <param name="query">PDF as Base64 string</param>
+    /// <param name="request">Request containing Base64-encoded PDF</param>
     /// <param name="cancellationToken">Cancellation token</param>
     /// <returns>PDF metadata (page count, file size, PDF version, attachments)</returns>
     /// <response code="200">PDF is valid, metadata returned</response>
@@ -69,10 +68,24 @@ public class PdfValidationController(IMediator Mediator) : ControllerBase
     [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
     [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
     public async Task<IActionResult> ValidateFromBase64(
-        [FromBody] ValidatePdfQuery query,
+        [FromBody] ValidatePdfBase64Request request,
         CancellationToken cancellationToken)
     {
+        // Convert Base64 to stream (wrap in try-catch to throw BadRequestException)
+        byte[] pdfBytes;
+        try
+        {
+            pdfBytes = Convert.FromBase64String(request.Base64Pdf);
+        }
+        catch (FormatException ex)
+        {
+            throw new BadRequestException("Invalid Base64 format: " + ex.Message);
+        }
+        
+        using var pdfStream = new MemoryStream(pdfBytes);
+        
         // Direct pass-through to MediatR
+        var query = new ValidatePdfQuery { PdfStream = pdfStream };
         var result = await Mediator.Send(query, cancellationToken);
         
         return Ok(result);
@@ -106,13 +119,11 @@ public class PdfValidationController(IMediator Mediator) : ControllerBase
             });
         }
 
-        // Convert IFormFile to byte array
-        using var memoryStream = new MemoryStream();
-        await file.CopyToAsync(memoryStream, cancellationToken);
-        byte[] pdfBytes = memoryStream.ToArray();
-
+        // Use IFormFile stream directly (no intermediate byte[] conversion)
+        using var pdfStream = file.OpenReadStream();
+        
         // Direct pass-through to MediatR
-        var query = new ValidatePdfAQuery { PdfBytes = pdfBytes };
+        var query = new ValidatePdfAQuery { PdfStream = pdfStream };
         var result = await Mediator.Send(query, cancellationToken);
         
         return Ok(result);
@@ -121,7 +132,7 @@ public class PdfValidationController(IMediator Mediator) : ControllerBase
     /// <summary>
     /// Validates a PDF/A document and checks conformance level (Base64 JSON)
     /// </summary>
-    /// <param name="query">PDF as Base64 string</param>
+    /// <param name="request">Request containing Base64-encoded PDF</param>
     /// <param name="cancellationToken">Cancellation token</param>
     /// <returns>PDF/A metadata (conformance level, errors, warnings)</returns>
     /// <response code="200">PDF/A validation completed, results returned</response>
@@ -133,12 +144,50 @@ public class PdfValidationController(IMediator Mediator) : ControllerBase
     [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
     [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
     public async Task<IActionResult> ValidatePdfAFromBase64(
-        [FromBody] ValidatePdfAQuery query,
+        [FromBody] ValidatePdfABase64Request request,
         CancellationToken cancellationToken)
     {
+        // Convert Base64 to stream (wrap in try-catch to throw BadRequestException)
+        byte[] pdfBytes;
+        try
+        {
+            pdfBytes = Convert.FromBase64String(request.Base64Pdf);
+        }
+        catch (FormatException ex)
+        {
+            throw new BadRequestException("Invalid Base64 format: " + ex.Message);
+        }
+        
+        using var pdfStream = new MemoryStream(pdfBytes);
+        
         // Direct pass-through to MediatR
+        var query = new ValidatePdfAQuery { PdfStream = pdfStream };
         var result = await Mediator.Send(query, cancellationToken);
         
         return Ok(result);
     }
 }
+
+/// <summary>
+/// Request DTO for Base64-encoded PDF validation
+/// </summary>
+public record ValidatePdfBase64Request
+{
+    /// <summary>
+    /// PDF document encoded as Base64 string
+    /// </summary>
+    /// <example>JVBERi0xLjQKJeLjz9MKMSAwIG9iago8PC9UeXBlL0NhdGFsb2c...</example>
+    public string Base64Pdf { get; init; } = string.Empty;
+}
+
+/// <summary>
+/// Request DTO for Base64-encoded PDF/A validation
+/// </summary>
+public record ValidatePdfABase64Request
+{
+    /// <summary>
+    /// PDF document encoded as Base64 string
+    /// </summary>
+    /// <example>JVBERi0xLjQKJeLjz9MKMSAwIG9iago8PC9UeXBlL0NhdGFsb2c...</example>
+    public string Base64Pdf { get; init; } = string.Empty;
+}
diff --git a/DocumentOperator.API/Controllers/SwissQrCodeController.cs b/DocumentOperator.API/Controllers/SwissQrCodeController.cs
index 3756ded..4770f9c 100644
--- a/DocumentOperator.API/Controllers/SwissQrCodeController.cs
+++ b/DocumentOperator.API/Controllers/SwissQrCodeController.cs
@@ -1,5 +1,6 @@
 using DocumentOperator.Application.Common.DTOs;
 using DocumentOperator.Application.SwissQrCode.Queries;
+using DocumentOperator.Domain.Common.Exceptions;
 using MediatR;
 using Microsoft.AspNetCore.Mvc;
 
@@ -17,7 +18,7 @@ public class SwissQrCodeController(IMediator Mediator) : ControllerBase
     /// Extracts Swiss QR Code from the last page of a PDF document (multipart/form-data)
     /// </summary>
     /// <param name="file">PDF file containing Swiss QR Code</param>
-    /// <param name="raw"></param>
+    /// <param name="raw">If true, returns raw QR text lines instead of parsed Bill object</param>
     /// <param name="cancellationToken">Cancellation token</param>
     /// <returns>Swiss QR Code data (IBAN, amount, creditor, debtor, reference, etc.)</returns>
     /// <response code="200">Swiss QR Code extracted successfully</response>
@@ -43,15 +44,13 @@ public class SwissQrCodeController(IMediator Mediator) : ControllerBase
                 Status = StatusCodes.Status400BadRequest
             });
 
-        // Convert IFormFile to byte array
-        using var memoryStream = new MemoryStream();
-        await file.CopyToAsync(memoryStream, cancellationToken);
-        byte[] pdfBytes = memoryStream.ToArray();
+        // Use IFormFile stream directly (no intermediate byte[] conversion)
+        using var pdfStream = file.OpenReadStream();
 
         // Direct pass-through to MediatR
         var query = new ExtractSwissQrCodeQuery 
         { 
-            PdfBytes = pdfBytes
+            PdfStream = pdfStream
         };
         var result = await Mediator.Send(query, cancellationToken);
 
@@ -61,8 +60,8 @@ public class SwissQrCodeController(IMediator Mediator) : ControllerBase
     /// <summary>
     /// Extracts Swiss QR Code from the last page of a PDF document (Base64 JSON)
     /// </summary>
-    /// <param name="query">References array + PDF as Base64 string</param>
-    /// <param name="raw"></param>
+    /// <param name="request">Request containing Base64-encoded PDF</param>
+    /// <param name="raw">If true, returns raw QR text lines instead of parsed Bill object</param>
     /// <param name="cancellationToken">Cancellation token</param>
     /// <returns>Swiss QR Code data (IBAN, amount, creditor, debtor, reference, etc.)</returns>
     /// <response code="200">Swiss QR Code extracted successfully</response>
@@ -76,13 +75,39 @@ public class SwissQrCodeController(IMediator Mediator) : ControllerBase
     [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
     [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
     public async Task<IActionResult> ExtractFromBase64(
-        [FromBody] ExtractSwissQrCodeQuery query,
+        [FromBody] ExtractSwissQrCodeBase64Request request,
         [FromQuery] bool raw = false,
         CancellationToken cancellationToken = default)
     {
+        // Convert Base64 to stream (wrap in try-catch to throw BadRequestException)
+        byte[] pdfBytes;
+        try
+        {
+            pdfBytes = Convert.FromBase64String(request.Base64Pdf);
+        }
+        catch (FormatException ex)
+        {
+            throw new BadRequestException("Invalid Base64 format: " + ex.Message);
+        }
+        
+        using var pdfStream = new MemoryStream(pdfBytes);
+        
         // Direct pass-through to MediatR
+        var query = new ExtractSwissQrCodeQuery { PdfStream = pdfStream };
         var result = await Mediator.Send(query, cancellationToken);
 
         return Ok(raw ? result.RawLines : result.Bill);
     }
 }
+
+/// <summary>
+/// Request DTO for Base64-encoded Swiss QR Code extraction
+/// </summary>
+public record ExtractSwissQrCodeBase64Request
+{
+    /// <summary>
+    /// PDF document encoded as Base64 string
+    /// </summary>
+    /// <example>JVBERi0xLjQKJeLjz9MKMSAwIG9iago8PC9UeXBlL0NhdGFsb2c...</example>
+    public required string Base64Pdf { get; init; }
+}