A DBS check has no official expiry date. Any information included will be accurate at the time the check was carried out. It's up to you to decide when a new check is needed. If the applicant has signed up for the DBS update service you can check whether their certificate is up to date online.
How long are DBS checks valid for?
While official recommendations suggest a DBS should be renewed every three years, some organisations have set policies surrounding when they request rechecks. This timescale can vary from six months to every two years.
Does a DBS ever expire?
In short, there are no official expiry dates on DBS checks, meaning your DBS certificate will still be valid. However, your certificate will state the date it was issued to you, which states that the DBS check is only truly accurate at that time of clearance.