What do I need to do if I have submitted a return using HMRC's 'Online Return and Forms – CIS' for the wrong month and year?
Contact the CIS Helpline on 0300 200 3210 and ask that the submitted return is corrected to show the correct return period. After that you'll need to send a paper return for the current period. The Helpline can issue you with a blank monthly return. After this you'll be able to submit your returns electronically but take care to ensure the return period shown is the correct one.
