A P11d is a HMRC form used by an employer to inform HMRC of any expenses and benefits that an employee has received throughout the year. It is for the purpose of those expenses and benefits that have, for whatever reason, not been processed through payroll.
Some common item that require a P11d form: health insurance, company car, loans exceeding £10,000 with no, or low interest rates, gym membership.
For employees/directors: These benefits are subject to PAYE and NIC – so you will see your tax codes change usually to account for this in future years. Make sure to keep an eye out for any letters or notifications through your Personal Tax Account about tax code changes – it is very easy to inform HMRC of an error (for example if you no longer receive a benefit). If you have to file a self assessment it is important you keep hold of your P11d as the details need to be submitted in your Self Assessment Tax Return.
For employers: This form is required to be submitted to HMRC by 5th July each year. As an employer, you will have to pay Class 1A NICs on these benefits and expenses. You will receive a penalty if you do not meet the deadline.