HM Revenue & Customs

As an Agent, do I need to obtain a declaration and keep a copy of my CIS client's Monthly Return before I file it online?

You don't need to keep paper copies of a return filed online. An agent can complete the online declaration on behalf of their client. However it is the client's (contractor's) responsibility to make sure the return is correct. For audit purposes, agents should keep a copy of the contractor's approval of the information.

Agents should also keep a copy of the return for the same time as the supporting records relating to the tax year period.