Does my employer have to let me carry forward my unused annual leave into the next holiday year?

It depends. 

Your basic statutory holiday entitlement under the EU Working Time Directive (four weeks of holiday) must be taken during the holiday year. Otherwise it will be lost.

The only exception is if you are unable to take your holiday because you are sick, injured, pregnant or on maternity leave. In these circumstances, you can carry forward your holiday into the next holiday year.

The right to carry forward holiday when you are sick is not without its limits. In a new ruling on Plumb v Duncan Print Group Limited UKEAT/0071/15/D, the Employment Appeal Tribunal said that holiday untaken due to sickness or injury can be carried forward for a maximum of 18 months after the end of the year in which it accrued. Any holiday left unused beyond that point is likely to be lost.

Under UK law, only the first four weeks of statutory holiday derive from the Working Time Directive. An extra eight days of leave derive from national law and result from trade union campaigning. The right to carry forward leave when sick or injured described above applies only to the four weeks of holiday based on the Working Time Directive.

If you are entitled to more than the statutory minimum amount of paid holidays then you may be able to carry the extra days forward (often called 'banking your leave'). This depends upon your contract of employment.

You should consult your company's staff handbook or your contract of employment for the policy at your workplace.

Note: This content is provided as general background information and should not be taken as legal advice or financial advice for your particular situation. Make sure to get individual advice on your case from your union, a source on our free help page or an independent financial advisor before taking any action.