Checksum
The MOD-97 standard (ISO 13616) catches almost all typos and transposed digits — a valid IBAN gives a remainder of 1 modulo 97.
IBAN Validator
Check whether an IBAN is valid and — for Bulgarian accounts — see the bank, branch and account number. Everything is computed in your browser.
🔒 Validation runs entirely in your browser. The IBAN is never sent or stored anywhere.
Structure (BG)
BG + 2 check + 4-letter bank + 4-digit branch + 2-digit type + 8-char account = 22 characters.
Which bank
The 4 letters after the check digits are the bank's BIC code — we map them to Bulgarian banks (indicative).
Frequently asked questions
How is an IBAN validated?
By the ISO 13616 (MOD-97-10) standard: the first 4 characters are moved to the end, letters are replaced by numbers (A=10 … Z=35), and the resulting large number must leave a remainder of 1 when divided by 97. The length must also match the country (22 characters for Bulgaria).
What does a Bulgarian IBAN consist of?
BG + 2 check digits + 4 letters (bank code, the first 4 of the BIC) + 4 digits (branch / BAE code) + 2 digits (account type) + 8 characters (account number) = 22 characters total.
How is the bank identified from an IBAN?
Characters 5–8 (right after the check digits) are the 4-letter bank identifier — the first 4 characters of its BIC/SWIFT code. The tool maps them to known Bulgarian banks. Because of mergers and rebrands the result is indicative only.
Does a valid IBAN mean the account exists?
No. The check is purely mathematical (format + checksum) and confirms the number is well-formed — not that the account is real or active. Only the bank can confirm that.
Does it work for non-Bulgarian IBANs?
Yes — the checksum and length are validated for every country with a registered IBAN format. Decoding the bank, branch and account is Bulgaria-specific.
Is the IBAN I enter stored?
No. The entire check runs in your browser — the IBAN is never sent to a server and nothing is saved.
This tool only checks the mathematical validity and structure of an IBAN — it does not confirm that the account exists and performs no bank lookup. Bank identification is by BIC prefix and may be inaccurate due to mergers.