# NFE-590

Source: https://xmlvalid.com/rules/NFE-590

> Rejeição: Informado CST para emissor do Simples Nacional (CRT=1 ou 4) [nItem: …] (CST …).

- Level: error
- Rule sets: SEFAZ authorisation rules of NF-e 4.00 MOC 7.0 Anexo I, NTs up to 2026.010
- Context: `nfe:infNFe/nfe:det`
- Test: `not($crt = ('1', '4')) or not($cst) or $cst = ('02', '15', '53', '61')`

In English: An issuer in the Simples Nacional (CRT 1 or 4) gives a CST; it takes a CSOSN, except the fuel CSTs 02, 15, 53 and 61.

Validate a document against these rules: https://xmlvalid.com/validate