How to Convert PDF Files to PDF/A

1. What Is PDF/A and Why Does It Exist?

PDF/A is a version of PDF specifically designed for long-term archiving. The "A" stands for Archive.

The problem it solves is straightforward: a standard PDF may rely on features that could become inaccessible in the future. A PDF that embeds audio requires a player. A PDF that uses a font stored on an external server requires that server to still exist. A PDF with JavaScript requires a compliant JavaScript engine. In ten, twenty, or fifty years, none of these can be guaranteed.

PDF/A solves this by restricting PDFs to only those features that are self-contained and likely to remain readable indefinitely. Everything the document needs to display correctly must be embedded in the file itself. Nothing can depend on external resources or future software capabilities.

The result is a document that can be reliably opened and read by any compliant PDF viewer, now or in the future, without needing plugins, internet connections, or specific software versions.

2. The Difference Between PDF and PDF/A

A standard PDF can contain almost anything — embedded video, audio, JavaScript, links to external resources, encryption, and transparency effects. This flexibility is useful for interactive documents, presentations, and digital-first content.

PDF/A removes this flexibility in exchange for preservation guarantees. Specifically, PDF/A prohibits:

If your PDF contains any of the prohibited features, converting to PDF/A will either remove them automatically or flag a conversion issue. The most common one that catches people by surprise: if your PDF is password-protected, the password must be removed before PDF/A conversion — because PDF/A files cannot be encrypted by design.

3. PDF/A Versions — Which One Do You Need?

PDF/A has three main versions, each with different levels of restriction and capability:

Which version to use: If a specific court, authority, or organisation requires PDF/A, check their documentation for which version they require — requirements vary significantly. If you are converting for general archiving without a specific requirement, PDF/A-2 is a reasonable default for most modern documents.

4. When Is PDF/A Actually Required?

PDF/A is not required for most everyday document sharing. It is specifically required or recommended in these contexts:

• Court and legal filings. Many court systems require PDF/A for electronic filing — particularly in the US federal courts, European jurisdictions, and other systems with formal e-filing platforms. The specific version required varies by court. Always check the court's filing guidelines.
• Government and regulatory submissions. Many government agencies, particularly in the EU, require PDF/A for official submissions. The ISO standard was adopted partly in response to government demand for a reliable archival format for official records.
• Long-term organisational archiving. Law firms, accounting firms, and any organisation that needs to retain records for ten years or more often standardise on PDF/A to ensure those records remain readable over time, regardless of how PDF software evolves.
• Electronic invoicing in some markets. ZUGFeRD (Germany) and Factur-X (France/Europe) electronic invoice standards use PDF/A-3 as the carrier format, with the invoice data embedded as an XML file.
• Libraries and archives. Institutional archives, libraries, and record offices typically require PDF/A for any digital document submissions intended for permanent preservation.

5. What Happens to Your File During Conversion

Converting a standard PDF to PDF/A is not a simple rename — it is a technical process that modifies the file to comply with the standard. Here is what actually happens:

• Fonts are embedded. If any fonts in your document are not already embedded, the converter embeds them. This ensures the document looks the same without requiring the recipient's device to have those fonts installed.
• Colour profiles are embedded. Colour information is standardised and embedded so the document displays consistently across different devices and colour environments.
• Metadata is added or reformatted. PDF/A requires document metadata in XMP format. The converter adds or updates this metadata to meet the standard.
• Prohibited features are removed. Encryption, JavaScript, audio, video, and external content dependencies are stripped. If your PDF has a password, you must remove it before conversion — a PDF/A file cannot be encrypted.
• Transparency may be flattened. In PDF/A-1, transparency effects are flattened — the visual result is preserved but the interactive transparency layer is removed.

The converted file should look identical or nearly identical to the original when viewed on screen. Any visible changes are the result of removing features (like encryption) or flattening effects (like transparency) that PDF/A does not support.

6. Did You Know?

7. Builder's Insight

PDF/A conversion was one of the tools I specifically added because it came up repeatedly in professional feedback — particularly from lawyers, archivists, accountants, and government-adjacent organisations who needed it for formal submissions or record keeping.

The honest technical reality of PDF/A conversion is that it works well for straightforward documents and can produce unexpected results for complex ones. A text-heavy report, a signed contract, or a simple financial statement converts to PDF/A cleanly in most cases. A document with extensive transparency effects, unusual colour spaces, or embedded multimedia will either have those features removed or may fail validation.

The most common issue I saw in testing: password-protected PDFs. People would try to convert a protected file to PDF/A and get confused when it failed or produced an error. PDF/A cannot be encrypted — it is part of the standard. The fix is simple: remove the password first using Unlock PDF (which runs locally, file never uploaded), then convert to PDF/A.

One thing worth being clear about: converting a file to PDF/A format does not automatically make it fully compliant with a specific court or regulatory requirement. Compliance depends on which PDF/A version the authority requires, whether the conversion was verified by a compliant validator, and sometimes on additional metadata requirements specific to that submission system. Always check the requirements of the specific system you are submitting to.

8. Step-by-Step: How to Convert PDF to PDF/A

9. Common Conversion Scenarios

Converting a contract for court filing

A signed contract needs to be filed with a court that requires PDF/A-2 submissions. The contract was password-protected before being signed.

1. Remove the password using Unlock PDF — local, no upload
2. Convert to PDF/A using PDF to PDF/A
3. Check the court's filing system requirements — confirm the version, any additional metadata required
4. Validate the converted file if the court provides or recommends a validator
5. Submit through the court's e-filing system

Archiving year-end financial documents

A set of year-end financial statements need to be archived for ten-year retention in a format that will remain readable regardless of future software changes.

1. Ensure the documents are finalised — PDF/A should be the last step, after all editing is complete
2. Convert each statement to PDF/A using PDF to PDF/A
3. Store the PDF/A files in your document management system with the retention period noted

Converting government submission documents

A regulatory filing requires PDF/A. The documents were created from Word and exported as standard PDFs.

1. Check the regulatory body's requirements — which PDF/A version, any metadata requirements
2. Convert each document to PDF/A
3. If the regulatory system has a validation tool, test the converted files before final submission
4. Keep the original standard PDF copies alongside the PDF/A versions for your own records

10. How Your File Is Handled

PDF to PDF/A uses server processing because the conversion requires a full PDF rendering and validation engine.

• Transfer: Your file is encrypted using TLS during transfer to our servers.
• Processing: The file is processed in temporary server memory and is not written to a permanent database.
• Deletion: Your file is automatically deleted from our systems within 24 hours — not on request, automatically.
• Human access: No one on our team opens or reviews file content. This is documented in our Privacy Policy.

For legal, regulatory, and archival documents that may be sensitive, read our Privacy Policy in full before uploading and make your own judgment about what is appropriate.

11. FAQs

12. Conclusion

PDF/A exists to solve a specific, real problem: documents that need to be readable in ten, twenty, or fifty years, regardless of how software changes. For court filings, regulatory submissions, institutional archiving, and long-term record keeping, it is often not optional — it is required.

The conversion process is straightforward for most documents. The most common issue to handle before converting is password protection — remove it first, since PDF/A cannot be encrypted. For complex documents with multimedia or extensive transparency, check the output carefully after conversion.

Always verify the specific version required by your submission system before converting, and use the system's own validation tools if they are available.