# NFE-680

Source: https://xmlvalid.com/rules/NFE-680

> Rejeição: Chave de Acesso referenciada em duplicidade na NF-e [nOcor: …].

- 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:ide/nfe:NFref/nfe:refNFe`
- Test: `not(../preceding-sibling::nfe:NFref/nfe:refNFe = .)`

> Rejeição: Chave de Acesso referenciada em duplicidade na NF-e [nOcor: …] (CT-e).

- 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:ide/nfe:NFref/nfe:refCTe`
- Test: `not(../preceding-sibling::nfe:NFref/nfe:refCTe = .)`

In English: The same key is referenced twice.

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