If you need to amend your Employer Annual Return after you've filed it with HM Revenue and Customs (HMRC) you must take the following steps:
Sending amended information means that your original return was either incomplete or inaccurate and could mean that you may be charged a penalty.
Amended information doesn't have to be filed using the same format you used for your original return. For example, if you used commercial payroll software to file your original return, you can send an amendment using HMRC's PAYE for Employers online service.
Please note: HMRC's PAYE for Employers online service is designed to be used for employers with 50 or less employees. You may not be able to use this service to amend P14's for more than 50 employees.
Contact details for HMRC's Customer Operations Employer Office can be found online.