PDF for .NET supports saving PDF documents to PDF/A. With PDF, you can now create, edit, and save PDF/A documents of all conformance levels. The support also includes Associated Files concept, which is needed to support embedded files in PDF/A-3 documents. You can embed files, images, txt, docx files, and more, and associate them with document elements. PDF/A-3a requires all content to be tagged, so you can add elements tagged as per PDF/A rules in the PDF/A documents.

PDF for .NET provides the ConformanceLevel property which sets the PDF/A conformance level using PdfAConformanceLevel enumeration to determine the PDF/A conformance levels. The following code showcases how to set the conformance level of a Pdf document to PDF/A 1b.

//Set the conformance level
pdf.ConformanceLevel = PdfAConformanceLevel.PdfA1b;