Where a worker is made redundant by their employer, they are entitled to be paid for any accrued but untaken holiday and any holiday taken but unpaid up to the point of their redundancy. Further guidance on how to calculate holiday pay and entitlement is available on GOV.UK and is kept under review.
On the 23rd July, the Department published updated guidance to clarify holiday pay for workers who are made redundant. This also includes when an employee is made redundant by an insolvent employer. The guidance can be found at https://www.gov.uk/government/publications/calculating-holiday-pay-for-workers-without-fixed-hours-or-pay
Employees who feel their rights have been denied may contact ACAS to receive free and impartial advice and may be able to bring a claim to an employment tribunal.