Compress PDF documents for HMRC, Customs Declaration Service, and UK government portals free online. Meet the 10MB file size limit instantly.

HMRC's Customs Declaration Service and most GOV.UK upload portals cap individual files at 10MB, with a maximum of 10 files per submission batch. If you're submitting invoices, licences, or supporting evidence for Self Assessment, VAT, or customs declarations, oversized scans are a common reason uploads fail or get rejected. ## HMRC and GOV.UK File Size Rules The Customs Declaration Service accepts up to 10 files per submission, each up to 10MB. If you need to send more than 10 documents, HMRC requires you to split them into separate groups of 10 or fewer — meaning oversized files compound the problem by forcing more separate batches. ## Steps to Compress PDF for HMRC Submission 1. Open [pdfhub24.com/compress-pdf](/compress-pdf) 2. Upload your scanned invoice, bill of lading, or supporting document 3. Choose **Standard Compression** for most documents — HMRC's 10MB limit is generous enough that high compression usually isn't necessary 4. Download and confirm the file is under 10MB 5. Repeat for each file, grouping submissions in batches of 10 or fewer as required by the Customs Declaration Service ## Government Gateway and Self Assessment Uploads If you're submitting documents through your Government Gateway account for Self Assessment, Corporation Tax, or VAT, the same principle applies — keep files well under any stated limit so the upload doesn't time out or fail silently. With GOV.UK gradually moving services to the newer One Login system through 2027, file handling on older HMRC services may behave inconsistently during the transition, so erring on the side of smaller, cleanly compressed files reduces friction. ## What Compresses Well for HMRC Documents Invoices, bills of lading, and licences are typically text and table-heavy with minimal imagery — these compress extremely well, often dropping 60-80% in size with no visible quality loss. Scanned signatures and stamps remain legible at standard compression. ## Multiple Documents in One Submission If a bill of lading, invoice, and licence belong together as one logical submission, HMRC treats them as a single file if combined into one PDF. Use [pdfhub24.com/merge-pdf](/merge-pdf) to combine them first, then compress the merged file once — this is often more efficient than compressing three separate files.