Guides & Explainers
Plain-language reference for the standards the StanzaAPI engines implement: IBAN, ANSI X12, ISO 20022, and GS1.
What Is an IBAN? Structure, Length, and Check Digits
An International Bank Account Number (IBAN) identifies a bank account across borders. It is a two-letter ISO 3166-1 country code, two ISO 7064 MOD-97 check digits, and a country-specific Basic Bank Account Number (BBAN).
Read the guide (5 min) →How to Calculate an IBAN Check Digit (ISO 7064 MOD-97-10)
IBAN check digits are computed with ISO 7064 MOD-97-10. Rearrange the string, convert letters to numbers, take the integer modulo 97, and subtract it from 98.
Read the guide (4 min) →ANSI X12 837 vs 835: Claims and Remittance Advice
The X12 837 is a healthcare claim submission; the X12 835 is the electronic remittance advice (ERA) that explains the adjudication. They are two halves of one round trip.
Read the guide (6 min) →X12 SNIP Validation Levels 1–6 Explained
SNIP is the WEDI framework for testing X12 healthcare transactions. Types 1 to 6 range from EDI syntax and guide compliance through balancing, code-set and payer-specific edits.
Read the guide (5 min) →ISO 20022: pain.001 vs pacs.008 Explained
ISO 20022 messages are grouped by family: pain for payment initiation, pacs for clearing and settlement, and camt for cash management. pain.001 starts the payment; pacs.008 carries it between banks.
Read the guide (5 min) →GS1 Application Identifiers (AI) Explained
A GS1 Application Identifier (AI) is a numeric prefix that defines the meaning and length of the data that follows it inside a GS1 barcode, such as a GTIN, batch, expiry date, or serial number.
Read the guide (6 min) →How to Validate a VAT Number (VIES and National Registers)
VAT number validation is two different checks: VIES confirms an EU VAT number is registered for intra-EU trade, while a national register confirms a domestic registration.
Read the guide (5 min) →What Is an LEI? ISO 17442 Structure and Check Digits
A Legal Entity Identifier (LEI) is a 20-character code that identifies a legal entity worldwide. ISO 17442 defines it, GLEIF-accredited Local Operating Units issue it, and its last two characters are MOD-97-10 check digits.
Read the guide (5 min) →How to Generate Valid Test IBANs for QA and CI
A test IBAN is a mathematically valid IBAN that is not a real bank account. A generator builds one from a country format plus a bank code, then computes the MOD-97 check digits so validators accept it.
Read the guide (4 min) →