International · Validation
Dutch BTW number validator.
Check a Dutch btw-identificatienummer (NL + 9 digits + B + 2 digits) against both known checksum styles. Format and checksum only.
How it works: the Belastingdienst format is NL, nine digits, the letter B and two digits. As implemented by python-stdnum, a number passes the checksum if the nine digits pass the BSN 11-test (older numbers) or NL plus the number passes ISO 7064 mod 97-10 (numbers issued from 2020).
Inputs
Result
Enter a number and press Check.
Dutch btw numbers: btw-id vs omzetbelastingnummer
The Dutch government’s business portal explains there are two numbers. The btw-identificatienummer (btw-id) is NL + 9 digits + B + 2 digits (example NL123456789B01); for a sole proprietorship it does not contain the BSN. The omzetbelastingnummer has no NL prefix (example 111234567B01) and, for a sole proprietor, is built from the BSN. For other legal forms the 9 digits come from the RSIN.
| Style | Test |
|---|---|
| Older numbers | The 9 digits pass the BSN 11-test: weights 9, 8, 7, 6, 5, 4, 3, 2, −1 sum to a multiple of 11 |
| 2020 onwards | NL + the 12 characters, with letters read as 10–35, give remainder 1 modulo 97 (ISO 7064 mod 97-10) |
python-stdnum doctests: 004495445B01 passes the 11-test; NL002455799B11 is documented as valid since 2020-01-01 (mod 97-10); 123456789B90 fails both, and a suffix of 00 is rejected. The two checks come from python-stdnum, not from a Belastingdienst publication, so a number that fails here but verifies in VIES should be trusted over this page.
Format and checksum only — not a VIES lookup
This tool does not contact VIES or the Belastingdienst. Use the VIES link above to confirm a number is currently registered. For the BSN itself see the Netherlands BSN validator; for other EU countries the EU VAT number validator.
Dutch BTW Number FAQ
What does a Dutch btw number look like?
The btw-id is NL, then 9 digits, the letter B and two more digits, for example NL123456789B01.
What is the difference between a btw-id and an omzetbelastingnummer?
The btw-id starts with NL and, for sole proprietors, no longer contains the BSN. The omzetbelastingnummer has no NL prefix and for sole proprietors is derived from the BSN.
Does a pass mean the number is active?
No. It only means the format and a checksum are consistent. Confirm an active registration in the EU VIES service.
Official register
To confirm a number is real, use the official source: EU VIES VAT number validation. Use the European Commission VIES service to confirm a number is active; this page never queries VIES.
Sources
- Ondernemersplein, nummers voor de btw (btw-id and omzetbelastingnummer formats; BSN not in the btw-id of a sole proprietorship); retrieved October 2026
- python-stdnum, stdnum/nl/btw.py (the two checksum styles and doctests); retrieved October 2026
Privacy and scope
This tool runs entirely in your browser: nothing you type is transmitted, stored, or logged, and it queries no government or commercial register. It checks format and checksum only and does not imply any official verification. Do not enter identity numbers belonging to other people that you have no reason to hold.