Employees who are in self-assessment generally claim employment expenses through their tax return. This may in turn lead to an adjustment of the PAYE code for subsequent years, but the claim still needs to be made on the return to ensure the tax deducted reconciles to the eventual liability. For those not in self-assessment, a claim can be made via their personal tax account, by phone, or by completion of a Form P87.

Currently, it's also possible to make a claim in writing, by using a letter to detail the expenses. This often happens where there are multiple years to claim for, or where a family member is helping another with their tax affairs. However, from 6 May this will no longer be possible, and HMRC will reject such claims. Instead, the P87 (which can be downloaded here) must be used. The other options, e.g. claiming via the personal tax account, will remain available.

The P87 form itself has been modified, and it will now be possible to claim for multiple years on a single form.