Summary
If your upload failed, it's almost always because the document doesn't meet Konfir's requirements. Here's what to check before trying again.
The most common reason: wrong document type
Konfir only accepts SA302 documents downloaded directly from your HMRC online account. The following are not accepted:
SA302s generated by accounting software (e.g. Xero, QuickBooks, FreeAgent, and others)
Alternative document types, including:
Tax Year Overview
Payslips
Bank statements
P60s or any other HMRC correspondence
If you uploaded one of these, download your SA302 from your HMRC online account instead. See What is an SA302 and where can I find it? for step-by-step download instructions.
Other reasons uploads fail
The file has been edited or modified
Konfir requires the original, unedited file. If you've annotated, redacted, or resaved the file (including "printing to PDF" from a viewer), download a fresh copy from HMRC.
Wrong file format
Files must be PDF, PNG, JPG, or JPEG. If your file is another format, download the PDF version directly from HMRC.
File too large
Files must be under 5MB. HMRC PDFs are usually well under this limit, so if yours is larger, try downloading it again rather than compressing it.
Slow or interrupted connection
If the upload timed out, try again on a stronger connection, or download the file to your device first and then upload from there.
If the upload keeps failing
Download a fresh SA302 from your HMRC online account
Check the file is an original, unedited PDF (not resaved or converted)
Confirm it's under 5MB
Try uploading again
If it still fails, skip the document upload step & submit your verification. Your verifier can contact you to arrange alternative verification method outside of Konfir.