Home/FAQ/What are CPF, PIX, SPEI, 3DS, card BINs and IFSC codes?
Explainer
What are CPF, PIX, SPEI, 3DS, card BINs and IFSC codes?
These pages answer “what is X”. The title is the question people search, the H2s answer it directly, and each article lists official links you can check. Spanish and Portuguese appear only where those queries are actually searched; Chinese and English match the rest of the site. India’s IFSC article has no reviewed Hindi translation, so it ships in English and Chinese only. This site is not a tax authority, central bank or card network and does not guarantee onboarding or payment results.
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Reviewed 14 October 2026
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- CPF and CNPJ
CPF and CNPJ are tax-identification registers run by Brazil’s federal revenue service (Receita Federal do Brasil). CPF is for natural persons; CNPJ is for companies and other legal entities. They are not card numbers and not a payment system. Banks, invoice desks and Pix often ask for one of them.
- RFC and CURP
CURP and RFC are two different Mexican official identifiers. CURP is the population-register key; RFC is the taxpayer number issued by SAT. Banks, payroll and invoicing may ask for both. One does not replace the other.
- PIX
Pix is the instant-payment arrangement created and overseen by Banco Central do Brasil. It moves funds between transactional accounts, including accounts at different institutions. It is not a cryptocurrency and not a card network. People, firms and government bodies can use it; features follow the participant and today’s Central Bank rules.
- SPEI and CLABE
SPEI is the interbank electronic payment system that Banco de México administers and operates. It moves Mexican pesos between accounts at different financial institutions inside Mexico. CLABE is the 18-digit standardised key that identifies the payee account. Neither is a card network, and neither is Brazil’s Pix.
- 3D Secure / 3DS
3D Secure — often written 3DS or EMV 3DS — is the e-commerce authentication protocol maintained by EMVCo to reduce card-not-present fraud. It lets the merchant and the issuer exchange data about the transaction, the payment method and the device so the issuer can confirm the payer is the cardholder. This site does not run live 3DS or ask for one-time codes.
- Card BIN
A card BIN is the prefix of a card number that identifies the issuing institution. The formal name in the international standard is Issuer Identification Number (IIN). Merchants, acquirers or issuers may accept or refuse whole BIN ranges, so an online payment is sometimes described as “declined by BIN”. This site cannot see scheme BIN tables and cannot promise the next charge.
- IFSC code
An IFSC — Indian Financial System Code — is the Reserve Bank of India’s alphanumeric code for a bank branch in its domestic payment systems. It names a branch, not a person, a tax account or a SWIFT/BIC. This site does not host RBI’s list and cannot confirm that a given string is still valid.
Questions and answers
- Do these pages guarantee an account or a payment?
- No. They only restate official definitions. Tax authorities, central banks, banks and card networks decide.
- Why is Portuguese or Hindi missing on some articles?
- Full text is written only in languages where the query is actually searched and the site already has a reviewed locale. Mexico and card-network topics ship Spanish and English; Brazil topics also ship Portuguese. Hindi routes have no reviewed translation, so IFSC is English and Chinese only.
- Where do fees and limits come from?
- Only facts that cite an official page. Unpublished fees, limits or statistics stay unknown.
Sources and review
Topic pages reviewed 14 October 2026. Sources include Receita Federal, SAT, Banco Central do Brasil, Banxico, the Reserve Bank of India, EMVCo and the ISO catalogue. Official texts can change. paytools.dev does not claim search rankings.