References are often asked for in job applications. There is usually no legal obligation to provide a reference.
ACAS have released new guidance on issuing references. The guidance covers:
What is an employment reference?
Does an employment reference have to be provided?
What can an employment reference include?
When are employment references needed?
Job offers and references
Can an employer give a bad reference?
Resolving problems with references
It is important to remember that employers who give references must make them fair and accurate and must handle them fairly and consistently. A copy of the guidance can be found here