The service accepted the file but processing stalled. Or the form rejected the upload with "invalid format." Or the document went through but an operator sent it back: "unreadable pages." These are all common upload failures, and most of them take five minutes to prevent before you hit send. Here is what to check.
Checklist before uploading
1. File size
Find out the maximum size the form accepts — it is usually shown near the upload button or in the instructions. If the PDF is over the limit:
- compress it with compress-pdf (works especially well on scanned documents);
- remove unnecessary pages with **remove-pages**;
- split the document with **split-pdf** if multiple files are allowed.
2. Correct format
Most forms accept a regular PDF. Some government portals require PDF/A. Check the requirements and convert if needed. If the form specifies a particular PDF version, confirm your file matches it.
3. Page order
Scroll quickly through the document: all pages are present and in the right order. If not, reorder with **organize-pdf** or fix the orientation with **rotate-pdf**.
4. Scan readability
Open the file at 100% zoom and check the key pages. Text should be readable without zooming in. Pay particular attention to names, dates, amounts, and signatures. A dark, skewed, or blurry scan is better re-scanned than returned by an operator.
5. Password
Most forms do not accept password-protected files. Check whether your PDF has a password. If it does and you have the right to work with the file, remove the protection with **unlock-pdf** before uploading.
6. Filename
Some systems do not handle non-ASCII characters, spaces, or long names well. A safe choice: a short name with no spaces, for example `passport_scan.pdf` or `contract_2026.pdf`.
7. Page count
If the form takes a single document, confirm all required pages are in one file. If there are too many pages, remove the extras.
Why a form rejects a file
The most common causes:
- **Over the size limit**: compress or split the file.
- **Wrong file type**: confirm the extension is `.pdf`, not `.jpg` or `.docx`.
- **File is encrypted**: remove the password.
- **Corrupted structure**: if the PDF does not open cleanly on your computer, try **repair-pdf**.
- **Temporary service error**: sometimes retrying the upload a few minutes later is all it takes.
To get a PDF ready for a portal or form upload, start with **compress-pdf** to cut down the size. For page order or orientation issues, use **organize-pdf** and **rotate-pdf**. To remove a password, use **unlock-pdf**.