LATAM context
Every Mexican bank account has a unique CLABE. The first 3 digits identify the bank (012=BBVA, 014=Santander, 002=Banamex, 072=Banorte, etc.), the next 3 the branch, the following 11 are the account number, and the last is a check digit, validated with a checksum algorithm.
Concrete example
CLABE 012180001234567890: 012=BBVA, 180=Mexico City clearing zone, 0012345678=account number, 90=check digit.
How it shows up on your bank statement
Your own account's CLABE usually sits in the statement header, next to the account number and the holder's name. Counterparties' CLABEs appear inside each SPEI transaction, identifying who you sent money to or received it from. Watch out: some banks mask the middle digits of your own CLABE in the PDF for security.
How does finO$ handle this?
finO$ extracts and validates the CLABE for every account and every counterparty in SPEI transfers, catching misscanned CLABEs by their check digit.