Penalties: culpability: on behalf of the taxpayer
The taxpayer cannot delegate responsibility for their own returns and accounts. A plea that errors or omissions are due to poor work by an accountant should normally be rejected.
Taxpayers should sign their own returns EM4815 and CT10323 and are required to sign the declaration that the return is to the best of their knowledge correct and complete. The taxpayer must take personal responsibility for the accuracy of the return and the declaration.
For the purposes of TMA70/S95, TMA70/S96 and para 89 penalties, any accounts submitted on behalf of any person are deemed to have been submitted by them unless they prove that they were submitted without their consent or connivance.
Normally, you should contend that the taxpayer remains responsible for the acts of their agent.