El código no es válido.

The code is not valid.

Breakdown of El código no es válido.

• ser: to be
• no: not
• válido: valid
• el código: the code

Questions & Answers about El código no es válido.

Why is it es and not está?

Spanish uses ser for classifications or inherent properties, so validity defaults to ser: El código no es válido. Use estar for states or availability. To highlight time-limited validity, you’d usually say no está vigente or ya no es válido, rather than no está válido (which is uncommon).

Why is válido masculine singular? How would it change with other nouns?

Adjectives agree with the noun in gender and number. Código is masculine singular, so válido is too.

• Feminine: La tarjeta no es válida.
• Plural masculine: Los códigos no son válidos.
• Plural feminine: Las claves no son válidas.

Can I say El código es inválido? Is there any difference from no válido?

Yes. Inválido and no válido both work. In interfaces and help texts, no válido is very common; inválido can sound a bit more formal/technical. Note the accent: inválido means “invalid”; without the accent (invalido) it’s the verb “I invalidate.”

Can I drop the article El? What about using este?