How to convert a pdf to pdf/a for government submission
- Step 1Check the portal's stated format requirement — Confirm whether the portal recommends or mandates PDF/A and whether it validates on upload. This tool targets PDF/A-1b. Companies House WebFiling recommends PDF/A; HMRC and Land Registry requirements vary by submission type — read the specific guidance.
- Step 2Remove any password — PDF/A forbids encryption, and most portals reject encrypted uploads anyway. Strip the password with PDF Remove Password first.
- Step 3OCR scanned forms if the portal needs searchable text — If you're filing a scanned form, run PDF OCR to add an invisible text layer before tagging. OCR re-emits each page as an image with the text layer drawn over it.
- Step 4Drop the file into the converter — Load the document. Tagging happens in your browser — nothing is uploaded. There are no options; the tool always produces PDF/A-1b.
- Step 5Convert and download — The tool adds the XMP
pdfaididentifier, the output intent, and the PDF-1.4 header, then re-saves. Download the tagged file. - Step 6Validate, then upload to the portal — Validate with veraPDF before submitting. If the portal runs strict validation, expect failures on the stub ICC profile and any non-embedded fonts — produce the upload copy with a certified converter in that case.
Common UK portals and their PDF/A posture
Requirements change — always read the portal's own current guidance before filing.
| Portal | PDF/A posture | Practical note |
|---|---|---|
| Companies House WebFiling | Recommends PDF/A for future-proof storage | Tag-only output is usually accepted; embed accounts fonts for faithful rendering |
| HMRC submissions | Varies by submission type | Check the specific service's file-format guidance |
| Land Registry (e.g. e-DRS) | Specifies acceptable formats per application | Tagging helps, but confirm the application type's exact rules |
| Public-sector DMS / records systems | Often mandate PDF/A for retention | Some run validation on ingest — confirm whether it's strict |
What the tool covers for a government upload
Each portal expectation mapped to whether the tag-only converter satisfies it.
| Expectation | Handled here | If not, do this |
|---|---|---|
| PDF/A identifier present | Yes | — |
| No encryption | Source must be decrypted | PDF Remove Password |
| Searchable scanned forms | Not added | PDF OCR first |
| All fonts embedded | Only if already embedded | Re-export with fonts embedded |
| Real ICC output intent | Stub only | Certified (Ghostscript / Acrobat) converter |
| Passes strict ingest validation | No | Certified converter for the upload copy |
Tier limits for government documents
PDF-family limits applied before conversion.
| Tier | Max file size | Max pages |
|---|---|---|
| Free | 2 MB | 50 pages |
| Pro | 50 MB | 500 pages |
| Pro + Media | 500 MB | 2,000 pages |
| Developer | 2 GB | 10,000 pages |
| Enterprise | Unlimited | Unlimited |
Cookbook
Real government-filing workflows and exactly what the converter changes in the uploaded document.
Tag company accounts for Companies House
Accounts exported from filing software usually already embed fonts. Tagging adds the PDF/A markers WebFiling recommends without altering the figures or layout.
Input: accounts-2025.pdf (fonts embedded, 0.9 MB)
Output: accounts-2025-pdfa.pdf
+ pdfaid:part=1, conformance=B
+ GTS_PDFA1 output intent
+ %PDF-1.4 header
Figures, tables, and layout unchanged.OCR a scanned form before submitting
A scanned paper form filed to a records system should be searchable. OCR first, then tag.
1. form-AP01-scan.pdf (image-only)
→ PDF OCR → form-AP01-searchable.pdf
(page image + invisible text layer)
2. → PDF to PDF/A → form-AP01-pdfa.pdfDecrypt before tagging
A password-protected statement from your accountant must be decrypted first, because PDF/A forbids encryption and portals reject encrypted uploads.
vat-return.pdf (password-protected) → PDF Remove Password → vat-return-open.pdf → PDF to PDF/A → vat-return-pdfa.pdf
What a portal's lenient check reads
A portal that only confirms the PDF/A identifier and output intent accepts the tagged file.
Ingest reads: XMP → pdfaid:part = 1, conformance = B OutputIntents → S = GTS_PDFA1 Header → %PDF-1.4 → Accepted.
What strict ingest validation flags
A portal validating with veraPDF catches the gaps. Plan around this where the portal is known to be strict.
veraPDF PDF/A-1B flags: 6.2.2 OutputIntent ICC invalid (stub) 6.3.x Font not embedded (if source lacked embeds) → Upload rejected; re-produce via certified converter.
Edge cases and what actually happens
Portal validates strictly on upload
rejectSome public-sector ingest systems run strict PDF/A validation. The stub ICC profile and any non-embedded fonts will fail, so the upload is rejected. Use this tool for internal tagging and produce the submission copy with a certified converter where the portal validates strictly.
Encrypted submission document
rejectPDF/A forbids encryption, and most government portals reject encrypted PDFs regardless. Strip the password first with PDF Remove Password or PDF Unlock.
Scanned form has no text layer
Not searchableA tagged image-only scan satisfies a lenient PDF/A check but isn't searchable. Run PDF OCR before tagging if the records system indexes document text. OCR rasterises each page and overlays an invisible text layer.
Accounts use non-embedded fonts
Not fixedIf your filing software exported with system fonts rather than embedding them, the converter won't add them, and the file fails the font-embedding rule. Re-export with 'embed all fonts' enabled before tagging so a future reader renders the accounts faithfully.
Portal mandates PDF/A-2b or PDF/A-3b
UnsupportedThis tool only writes the PDF/A-1b identifier. Some retention systems mandate 2b (transparency, embedded files) or 3b (attachments such as the source XBRL). It cannot target those — use a converter that supports the mandated part.
Free-tier 2 MB / 50-page cap exceeded
BlockedFull annual accounts or large form sets exceed the free-tier 2 MB / 50-page limit. Upgrade to Pro (50 MB / 500 pages) or higher, or split before tagging. Portals often impose their own size caps too.
Transparency in a letterhead or watermark
Not flattenedPDF/A-1 forbids transparency and this tool does not flatten it. A 'DRAFT' watermark or a logo with a transparent background carries transparency into the output and fails strict 1b validation. Flatten in the source application first.
Digitally signed return
Signature brokenRe-saving changes the bytes and invalidates any existing signature. Convert first, then re-sign the archival copy with PDF Digital Signature if the portal requires a signed file.
Custom retention-schema metadata
ReplacedThe converter writes its own XMP packet. Retention codes or department IDs stored in custom XMP fields are not preserved — re-apply them after conversion or carry them in the portal's own form fields rather than the file metadata.
Frequently asked questions
Does Companies House require PDF/A?
Companies House WebFiling recommends PDF/A so uploaded documents are stored in a future-proof format. It's a recommendation rather than a hard requirement for every document type, so a tag-only PDF/A-1b file is generally accepted — but always check the current WebFiling guidance for the specific form you're filing.
Does the government portal check PDF/A compliance on upload?
Some portals run automated validation on ingest; others accept any PDF but prefer PDF/A. If a portal validates strictly, the stub ICC profile and any non-embedded fonts in this tool's output will fail. Find out whether your portal validates strictly and, if so, use a certified converter for the file you actually upload.
Which PDF/A level does this produce?
PDF/A-1b only — pdfaid:part=1, conformance=B. It cannot produce 1a, 2b, or 3b. If a records system mandates a later part (for example 3b to attach source data), use a converter that supports it.
Can I convert a password-protected PDF for government filing?
No — PDF/A forbids encryption, and portals generally reject encrypted uploads. Remove the password first with PDF Remove Password or PDF Unlock, then tag the decrypted copy.
Is my filing uploaded to a server?
No. Tagging runs entirely in your browser; the document never leaves your device. Only an anonymous usage counter is recorded when you're signed in, with no content. That keeps personal and commercial data off third-party servers, which matters under UK GDPR.
Should I OCR a scanned form before converting?
If the records system indexes document text, yes — run PDF OCR to add a searchable text layer, then tag. OCR re-emits each page as an image with an invisible text layer drawn on top, so the form looks identical but becomes searchable.
Will my accounts render identically to a reviewer in twenty years?
Only if the fonts are embedded. The converter preserves fonts already embedded in the source but does not add missing ones. Re-export your accounts with 'embed all fonts' enabled before tagging to ensure faithful long-term rendering.
How do I validate the output?
Run it through veraPDF using the PDF/A-1B profile. Expect it to pass the XMP-identifier rules and fail on the ICC profile (stub) and any non-embedded fonts. If your portal validates with the same engine, that tells you whether the upload will be accepted.
What file size can I convert?
Free tier is 2 MB / 50 pages, Pro 50 MB / 500 pages, Pro + Media 500 MB / 2,000 pages, Developer 2 GB / 10,000 pages, Enterprise unlimited. Portals usually have their own per-file caps as well.
Will signing the document break PDF/A status?
Sign after converting, not before. Re-saving during conversion invalidates an existing signature, so convert to PDF/A first and then apply the signature to the archival copy with PDF Digital Signature.
Can I keep the original after filing?
Yes, and you should. Retain the original alongside the tagged copy for your own records. If a portal later asks for a stricter PDF/A pass, you'll want the source to re-produce the file rather than repair the tagged version.
Can I tag many filings at once?
The browser tool processes one file per run; Pro and above allow small batches (Pro 5, Pro + Media 50). For a high-volume filing pipeline, pair the @jadapps/runner and POST each file to the local pdf-to-pdfa endpoint so documents stay on your machine.
Privacy first
All PDF processing runs locally in your browser using PDF-lib and pdf.js. No file is ever uploaded — only metadata counters are saved for signed-in dashboard stats.