Deductions From Pay
Other than tax, NI, court orders, etc. the employer needs your written agreement to any deductions from before that deduction is made. Otherwise it is likely to be an unlawful deduction.
Failure to pay money you are owed is treated in the same way. This applies to days you worked or were available for work (including periods of suspension); bonuses; notice pay and holiday pay.
You can only take a claim for money owed to you if you have first put in a formal written grievance asking for these amounts to be paid to you. So you may benefit from having yours professionally written. Please see also our section on Grievances (tab at top of page).