March 27, 2026 (Updated)
You have scanned all your supporting documents, opened the government's online application portal, and found the upload field. Then you spot the fine print: "Maximum file size: 2MB per attachment." Your scanned PDF is 15MB.
Government upload systems are notorious for strict file size limits, and many give you nothing more than a generic "upload failed" message. Below is a verified reference table of actual limits across government systems (with official sources), plus strategies to compress your PDF to fit.
Government System Upload Limits
The following data comes from official documentation and system guidelines. Last verified: March 2026.
| System | Upload Limit | Notes |
|---|---|---|
| Tax filing attachments (Taiwan) | 15MB / household | Raised from 10MB starting tax year 2023; JPG, PNG, PDF only |
| Immigration Agency (Taiwan) | 512KB / file | PDF, JPG, PNG, BMP accepted |
| National ID photo upload | 5MB / photo | JPG only; must visit office within 5 days |
| NHI card photo upload | 5MB | JPG, JPEG, GIF, PNG |
| Judicial Yuan e-filing | ~50MB / file | IP, tax, and civil litigation cases |
| Online document signing (national standard) | 10MB | Document body + attachments combined |
| Inter-agency document exchange | 2MB | Body + attachments combined; oversized files go to shared download |
| MOEA electronic documents | 2MB | Body + exchange form + attachments combined |
| NSTC report upload | 10MB | - |
Sources: Ministry of Finance, Immigration Agency, Household Registration, NHI Administration, Judicial Yuan FAQ, NDC Document Management Regulations
Strictest limit: Immigration Agency at 512KB. A single color scan at 300 DPI is about 8MB -- compressing that to 512KB requires aggressive optimization. If you are applying for residence or business visas, prepare your documents in advance.
Why Are Government Limits So Small?
It is not that agencies are trying to make your life harder. According to the National Development Council's "Regulations on Computerized Document and Archives Management," inter-agency electronic document exchange has a 2MB combined limit. This standard was set when bandwidth and storage were expensive, and it remains the design baseline for many systems today.
Government IT procurement cycles are long -- changing a file size limit might require months of approval. The good news is that some systems are loosening up: the tax filing system raised its limit from 10MB to 15MB starting in 2023.
How to Compress to a Specific Target
Using PDF Under's compress tool:
- Drag your PDF into the upload area
- Set your target size -- aim slightly below the limit. If the portal allows 2MB, set 1.8MB. If the limit is 1MB, target 900KB. For the Immigration Agency's 512KB, set 450KB. This buffer prevents landing right on the boundary
- Click compress and wait for processing
- Download the compressed PDF
Before uploading, check the file size on your computer to confirm it is under the limit.
Will Text Still Be Readable at 1-2MB?
That depends on how many pages you are compressing into that space.
A 3-page document compressed to 2MB gives each page roughly 660KB of data. At that level, quality loss is minimal. Text is crisp, stamps are clear, signatures are legible.
A 10-page document at 2MB means roughly 200KB per page. Text is still readable at normal zoom, but things get noticeably softer if you zoom in. Stamps and handwritten notes may lose some detail.
A 20-page document at 2MB starts to push the limits of readability. At that point, consider splitting the document into parts (if the portal accepts multiple attachments) using the split tool, then compressing each part separately.
Compression Strategy by System
| System | Limit | Suggested Target | Strategy |
|---|---|---|---|
| Tax filing | 15MB / household | 12MB | Usually straightforward; plenty of headroom |
| NSTC reports | 10MB | 8MB | Chart-heavy reports may need lower DPI |
| Document signing | 10MB | 8MB | Watch combined size with multiple attachments |
| ID/NHI photo | 5MB | 3MB | JPG format; phone photos usually fine |
| Document exchange | 2MB | 1.5MB | Scan at 150 DPI grayscale |
| Immigration Agency | 512KB | 450KB | Essential pages only; 150 DPI grayscale |
Getting the Best PDF Quality Within Size Limits
Compression is not a one-size-fits-all process. Different document types benefit from different strategies, and the key factor is DPI (resolution).
How DPI Affects File Size
For A4-sized pages, approximate file size per page:
| DPI | Color (per page) | Grayscale (per page) |
|---|---|---|
| 150 DPI | ~200-400KB | ~80-150KB |
| 200 DPI | ~400-800KB | ~150-300KB |
| 300 DPI | ~800KB-2MB | ~300-600KB |
Calculating Your Per-Page Budget
Target size / number of pages = per-page budget
Example: compressing a 10-page document for the 2MB inter-agency exchange limit (target: 1.5MB). Per-page budget is 150KB. That is roughly 150 DPI grayscale quality -- fine for text-only documents, but stamps and handwritten signatures may lose some detail.
The Immigration Agency's 512KB limit is even more extreme: 3 pages at 450KB target gives just 150KB per page. Use 150 DPI grayscale and include only essential pages.
Recommendations by Document Type
- Text-heavy official documents (applications, contracts, certificates): 150 DPI grayscale is sufficient. Text remains crisp on screen
- Documents with photos (photo evidence, site photos): 200 DPI color is a good balance
- Documents with stamps and signatures: Keep 200 DPI or above. If space is tight, compress other pages first and preserve stamp page quality
- Scanned documents: If you can re-scan, scan at the appropriate DPI directly. Use 150 DPI grayscale for text, 200 DPI color for documents with photos
When setting your target size in PDF Under's compress tool, aim for 90% of the limit -- set 1.8MB for a 2MB limit, 450KB for the 512KB limit.
Practical Strategies
- Test first: if you are not sure what the limit is, try uploading your original file. Some systems will tell you the exact limit in the error message
- Compress each document separately: if you need to upload five supporting documents, compress each one individually. Do not merge them first -- separate compression produces better results
- Consider grayscale: if your documents are black text on white paper (which most official forms are), scanning in grayscale dramatically reduces file size
- Keep the originals: use compressed versions for uploading only. Keep full-quality copies for your records
When Compression Is Not Enough
In rare cases -- say a 30-page document with a 512KB limit -- compression alone may not produce acceptable quality. Fallback options:
- Upload only the required pages: use the split tool to remove cover pages, blank pages, and anything not strictly needed
- Upload in parts: if the form allows multiple attachment fields, split your document and compress each section
- Re-scan at lower resolution: 150 DPI in grayscale produces much smaller files and is perfectly readable on screen
- Contact the agency: sometimes staff can accept documents via email or in person as an alternative to the online portal
Government upload limits are a genuine headache, but in most cases, three minutes with a compression tool is all it takes to get your documents through.