How long is a land survey good for?

A survey doesn't "expire" the way a license does. It accurately shows conditions as of the date of the field work ^[1].

It may still be useful if:

• no buildings, fences, driveways or additions have changed on your lot or right next door,
• the corner monuments are still in place, and
• the lender or title company will accept it, often with an affidavit of no change.

You'll likely need a new or updated survey when:

• improvements have been added or removed,
• monuments are missing,
• a lender, title company or permit office requires a recent survey, or
• you're buying and the survey isn't certified to you ^[2].

Ask the original surveyor about an update. They have the records and may charge less than a new survey would cost.