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) →Adversarial Test Data: How to Fuzz a Regulated Parser
Adversarial test data is input designed to make a parser fail dangerously — not merely to make it error. It covers injection, resource exhaustion, encoding attacks, validation bypass, structural confusion, and prompt injection for AI agents.
Read the guide (12 min) →ISO 6346 Container Check Digit: How It Is Calculated
A container number is an owner code, an equipment category, a six-digit serial, and a single ISO 6346 check digit computed from a weighted sum modulo 11.
Read the guide (4 min) →IATA Air Waybill Check Digit (MOD-7) Explained
An air waybill number is a three-digit airline prefix, a seven-digit serial, and a check digit computed by weighting the serial digits 8 to 2 and taking the remainder modulo 7.
Read the guide (4 min) →What Is a UDI? Device Identifiers Across GS1, HIBCC, and ICCBBA
A Unique Device Identifier is a device identifier (the model) plus production identifiers (lot, serial, expiry), carried in one of three issuing-agency syntaxes: GS1, HIBCC, or ICCBBA.
Read the guide (5 min) →What Is CBAM? The EU Carbon Border Adjustment Mechanism
The Carbon Border Adjustment Mechanism is the EU tool that prices the embedded carbon in imported goods, starting with cement, iron and steel, aluminium, fertilisers, electricity, and hydrogen.
Read the guide (5 min) →What Is Peppol? The EU e-Invoicing Network Explained
Peppol is an international network for exchanging structured business documents. Senders and receivers connect through certified access points, and invoices follow the Peppol BIS Billing profile over the EN 16931 semantic model.
Read the guide (5 min) →What Is Factur-X? ZUGFeRD and the Hybrid e-Invoice
Factur-X, known as ZUGFeRD in Germany, is a hybrid e-invoice: a PDF/A-3 file with an embedded UN/CEFACT Cross Industry Invoice XML that machines read while humans see the PDF.
Read the guide (4 min) →What Is EPCIS? GS1 Supply-Chain Event Data Explained
EPCIS is the GS1 standard for capturing and sharing supply-chain events. Each event records what happened, to which items, where, when, and in what business step.
Read the guide (5 min) →