CST

Validate

• JavaScript library
• Python library
• Go library5 cases fail
• Ruby library32 cases fail
• Rust library
• .NET library26 cases fail
• Erlang library

Checks whether a CST code is valid for a tax.

• options.tax picks the table: icms, ipi, pis or cofins (PIS and COFINS share a table). When options.tax is omitted or unknown, the function accepts a code that exists in any of the tables.
• For icms the code is one of the 15 Tabela B codes of 2 digits (00, 02, 10, 15, 20, 30, 40, 41, 50, 51, 53, 60, 61, 70, 90), bare as the NF-e CST field carries it next to orig, or the 3-digit form with an origin digit 0-8 before it. 02, 15, 53 and 61 are the monofasia de combustíveis codes that Ajuste SINIEF 39/23 added; 12, 13, 52, 72 and 74 are not codes, because Ajuste SINIEF 20/24 struck them before they took effect.
• ipi accepts 14 codes of 2 digits: 00-05, 49, 50-55 and 99. pis and cofins accept 33 codes of 2 digits: 01-09, 49, 50-56, 60-67, 70-75, 98 and 99. These taxes have no 3-digit form.
• Accepts a string or a safe non-negative integer. The 3-digit ICMS form accepts any run of separators (space, ., - or /) right after the origin digit ("1--10", "0 . 10"). A separator anywhere else is rejected ("0-0", "00-", "11-0"). Surrounding whitespace is ignored. Any other string ("abc110") is rejected, its digits are not picked out.
• A single digit is padded to the 3-digit ICMS form (0 and "0" are 000, also for the other taxes, so a single digit is never an IPI, PIS or COFINS code). A 2-digit value is a Tabela B code, read as written and never as origin plus a digit: isValidCst("10", { tax: "icms" }) is the Tabela B code 10, and "07" is not an ICMS code. The number 7 is read as 007, not as 07.
• A null or non-object options is read as no options, so every table is checked (until 2.4.0 it made the result false).
• Until 2.4.0 a 2-digit value was never a valid ICMS code ("10", "00" with tax: "icms" were false) and only one separator was accepted after the origin digit ("1--10" was false). Both changed in 2.5.0.
• Sources: the ICMS Tabela B of Convênio SINIEF s/nº 1970 as Ajuste SINIEF 39/23 gave it and Ajuste SINIEF 20/24 amended; IPI, PIS and COFINS from Instrução Normativa RFB nº 1.009/2010.

import { isValidCst } from '@brazilian-utils/brazilian-utils';

isValidCst('000', { tax: 'icms' }); // true
isValidCst(0, { tax: 'icms' }); // true (a single digit is padded to the 3 digit form, '000')
isValidCst('0', { tax: 'icms' }); // true (padded the same way a number is)
isValidCst('110', { tax: 'icms' }); // true
isValidCst('002', { tax: 'icms' }); // true (monofasia de combustíveis)
isValidCst('60', { tax: 'icms' }); // true (a bare Tabela B code, as the NF-e CST field carries it)
isValidCst('06', { tax: 'pis' }); // true
isValidCst('99', { tax: 'ipi' }); // true
isValidCst('110'); // true (found in the icms table, tax omitted)
isValidCst('000', { tax: 'nope' }); // true (an unknown tax falls back to every table)
isValidCst('999'); // false (not in any table)
isValidCst('abc110'); // false (not a documented form)
isValidCst(-110); // false (not a non-negative safe integer)