P46 upload for Tax year

Hello. I am enquiring to see if I can upload my employees car benefit in kind details for the current year. When I try to upload the details on the P46 form it states the P11D has been submitted already and I cannot proceed. Could someone please advise how I can change the P11D year and add the new employees car details to update HMRC?

Hi,

Please contact our Employers team to discuss. 

Employers: general enquiries

Thank you.