Will old final written warning come back to bite?

[RainbowMe]

My husband made a really silly mistake at work over 5 years ago and it resulted in a final written warning. Since then, he has generally received excellent feedback in all 1:1s, annual reviews etc, has won awards for his work and has been promoted twice. He is now looking to move on to another job in a different company, but is worrying that the old warning may come back to haunt him when references are requested. His company's policy is to purely state what job the person did and in what time period, but of course other employers may send a form which specifically asks about disciplinary history. The disciplinary was "active" for 2 years but I'd imagine will still be on file somewhere. He works in finance but not in a particularly senior position (he was in a very basic, entry-level role at the time of the mistake). Does anyone know how worried we need to be about this?

The warning is no longer live and therefore should not be declared.

Most employers will only state dates of employment and role, regardless of what is requested.

Don't worry about it OP. Legally they cannot share anything that has expired, and if that warning is five years old it definitely will have expired. They also need your permission to share any information.
Most employers only give basic references anyway which confirm dates and capacity of employment.

As PP said the warning has expired.

Generally HR only give out employment dates etc. It’s becoming too complex to state more, both volume wise and risk.

Thanks so much all, that is incredibly reassuring! :)