How do I use my mainland China tax payment certificate for Taiwan tax credit?
Get the tax payment certificate (完税证明) from the mainland tax bureau, have the document verified through the Straits Exchange Foundation (海基会) channel, then claim the foreign tax credit on your Taiwan return. The credit is capped — it can't exceed the Taiwan tax payable on that same income. Start early: cross-strait document flows are slow, and missing Taiwan's May filing deadline means losing the credit for the year.
The credit cap
Taiwan's foreign tax credit works like most countries': you can credit the mainland tax paid, but only up to the amount of Taiwan tax attributable to that foreign-source income. If you paid more in China than Taiwan would charge on the same income, the excess doesn't carry forward — it's lost.
| Step | What to do |
|---|---|
| 1. Get the certificate | Request the 完税证明 from the mainland tax bureau where the tax was paid |
| 2. Verify the document | Mainland-issued documents for use in Taiwan go through the SEF (海基会) verification channel |
| 3. Claim on the return | Attach the verified certificate to your Taiwan individual income tax return (filed May 1–31) |
Why the verification step exists
Taiwan doesn't directly accept mainland official documents. The SEF verification (验证) authenticates that the certificate is genuine. This adds weeks to the process — the most common failure mode is starting in April and discovering the paperwork won't be back before the May 31 deadline.
Timing strategy
Request the mainland certificate as soon as the mainland tax year settles (after the March–June settlement, or immediately for withholding taxes already final). Begin SEF verification the moment you have it. If verification won't complete in time, file the Taiwan return on schedule and consider an amended return once documents arrive — but confirm the amendment window with your CPA first.
Worked example: the cap in action
Suppose you paid RMB 100,000 in mainland IIT on salary income, and the Taiwan tax computed on that same salary is NT$280,000. You can credit the full RMB 100,000 (converted at the applicable rate). But if the Taiwan tax on that income were only NT$200,000-equivalent, your credit caps there — the extra mainland tax paid is simply unrelieved. This is why high mainland effective rates on the same income can leave money on the table.
Frequently asked questions
Can I claim the credit without the SEF verification?
In practice, no — the tax office will ask for verified documents. Unverified certificates are routinely rejected.
What if I missed the May deadline?
You may still be able to file an amended return (更正申报) within the allowed period. Don't assume the credit is lost forever, but don't delay either.
Does the cap apply per income item or in total?
It's computed on the foreign-source income included in the return — effectively, Taiwan won't subsidize foreign tax above its own rates. Keep the mainland and Taiwan income breakdowns consistent.
Sources
- https://www.seftb.org/cp-4-1638-e2ef8-1.html
- Taiwan Income Tax Act — foreign tax credit provisions; MOF guidance on cross-strait document verification