Essentially, a conviction cannot become spent until the order ends. Some orders run for many years longer than the 'main' sentence. If someone received a 4 month prison sentence, this would be spent 2 years after the end of the full sentence.

How do I know if my conviction is spent?

If you're still in your rehabilitation period following a criminal conviction, your conviction is unspent. Any custodial sentence over two and a half years stays unspent. If you were found guilty of a criminal offence by a court, following the specified time-period, your conviction will be considered “spent”.

How long does a conviction last on record?

Although convictions and cautions stay on the Police National Computer until you reach 100 years old (they are not deleted before then), they don't always have to be disclosed. Many people don't know the details of their record and it's important to get this right before disclosing to employers.