South Korea: the electronic tax invoice
In South Korea, per the summaries read, VAT tax invoices must be issued electronically and reported to the National Tax Service by the next day: always for corporations, and for individual businesses above a prior-year sales threshold (KRW 80 million, as reported). Below: how it works as secondary summaries describe it, where this page’s knowledge is thin, and a local check of a business registration number’s check digit.
How it works (as secondary summaries report)
| Step | What happens |
|---|---|
| Issue | The seller issues the tax invoice as structured data through the NTS Hometax portal or a certified service provider (ASP), signed with a certificate. |
| Report | A copy goes to the NTS by the day after the issue date. Reported consequence of missing the issue or the report: a percentage-of-supply-value penalty (rates unread here). |
| Who | All corporations; individual businesses once their prior-year supply value passes a threshold, reported as KRW 80 million from 1 July 2024 (KRW 100 million before, KRW 300 million before that). |
| Identify | Seller and buyer are identified by the 10-digit business registration number. |
| Buyer | The buyer’s input VAT deduction relies on a valid tax invoice; the exact conditions were not read. |
Written from memory of secondary summaries (vendor and adviser guides), not from the Act, NTS notices or Hometax pages, none of which were read for this page. The thresholds, the one-day report deadline and the penalty rates may have changed; treat every date and figure as a lead to check.
Check a business registration number
Tests the shape (10 digits; spaces and hyphens are ignored) and the check digit. It does not look anything up, so it cannot say whether the number is registered, active, or belongs to the name on the invoice.
The rule (first nine digits weighted 1, 3, 7, 1, 3, 7, 1, 3, 5, plus the integer part of the ninth digit times 5 over 10, tenth digit = 10 minus the sum mod 10, mod 10) is the one the python-stdnum library documents for Korean business numbers. It was not read from the NTS specification.
What this checker does and does not cover
The main checker reads UBL, CII and Factur-X and applies EN 16931 and Peppol rules. It does not read the Korean tax invoice XML, call Hometax or the NTS, or have Korean codes. Treat the number test here as a typo catch only.
Test a file before you send it
For a European or Peppol invoice, open the checker, drop your XML and read the findings, each with a rule ID and a fix (the rule reference). No account, nothing uploaded. No invoice yet? The e-invoice creator turns a form into UBL or CII XML and checks it. Other countries: all mandates by country.
Common questions
What is South Korea's electronic tax invoice?
A VAT tax invoice issued as structured data through the National Tax Service's Hometax portal or a certified service provider, with a copy sent to the NTS by the day after the issue date. Corporations must use it; individual businesses must once their prior-year supply value passes a threshold. This is how the rule is usually summarised; the statute and NTS notices were not read for this page.
What is the threshold for individual businesses?
Summaries say KRW 80 million of supply value in the prior year from 1 July 2024, lowered in steps from KRW 300 million, and that the test is applied to the year before. The figure comes from memory of secondary summaries, not from an NTS notice; check the NTS before relying on it.
What is a valid Korean business registration number?
It has 10 digits, written 123-45-67890. Multiply the first nine digits by 1, 3, 7, 1, 3, 7, 1, 3, 5, add the integer part of the ninth digit times 5 divided by 10, and the tenth digit must equal 10 minus the sum's last digit, taken mod 10. A match does not mean the number is registered or belongs to the name on the invoice.
Can this checker validate a Korean tax invoice?
No. It does not read the Korean XML standard, does not call Hometax, and has no Korean rules. It tests a business registration number's shape and check digit on this page, and a clean result is not an approval by the National Tax Service.
Open the E-invoice Preflight checker to validate your own invoice file.
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