A background check is done by employers to ensure all of the information supplied by potential employees is accurate If relevant it will include checks to ensure they have the necessary visas etc to work in the UK.
What is a background check?
There are many reasons why somebody might want to run a background check but we are focusing here on background checks run by employers on potential employees.
Employers must run background checks on potential employees. This needs to be done to ensure all information provided by the candidate is accurate. Also in many cases, employers are legally obliged to run background checks.
The answer to the question what is a background check is the same for all employers but the answer to the follow on question  what is checked in a UK employee background check will vary depending on the job been filled.
The following handy guide will outline why people run background checks but will also show what is checked depending on the job on offer.
Now you know what is a background check and more importantly what comes up in a background check. Employers need to have a good reason to do a background check. The UK law is very clear on what can be checked. This article on Checks employers can make on job applicants is worth reading.