The Disclosure and Barring Service (DBS) helps employers make safer recruitment decisions and prevent unsuitable people from working with vulnerable groups, including children. It replaces the Criminal Records Bureau (CRB) and the Independent Safeguarding Authority (ISA).
A DBS check has no official expiry date. Any information included will be accurate at the time the check was carried out. However, as a general rule, if your certificate is older than 6 months and you are asked to provide it, you will probably have to apply for a new one.
Having a DBS check certificate to show to prospective clients may help ease their minds if they want you to work with their children.
In England and Wales you can get a 'basic check' with details of any unspent convictions from gov.uk.
In Northern Ireland you can get various checks from nidirect.
In Scotland you can get a 'basic disclosure' with details of any unspent convictions from mygov.scot.
On scouring the Internet we have discovered a multitude of sites that offer - for a fee - to get you a personal DBS check.
However, we don't know if they can deliver on their promises or which is the best one to use.
So if you do require any further details then have a look at Apply to check someone else's criminal record and Disclosure & Barring Service before you make a decision.