During your maternity leave, your holiday entitlement remains the same as if you were still at work. This means you still accrue holiday days during the time you are away from work.
Although you cannot take holiday days or receive holiday pay during your maternity leave, you are able to arrange with your employer to take holiday days before or after your leave. You should ask your employer to confirm how much holiday entitlement you'll accrue before and during your planned maternity leave.
Your employer should allow you to carry over up to 5.6 weeks of unused days (28 days if you work five days a week) into your next holiday year if you are unable to take your holiday due to maternity leave.