Up to two thirds of the 8 million earners on the new form of assessment have not yet filled in their forms as the deadline of 30 September approaches.
Peter Black, a former Inland Revenue deputy controller who has set up a self-assessment advisory company, Simplitax, said: "By the end of the month there will be absolutely no help available for those who find the new forms daunting and difficult to understand.
"This means that after 30 September revenue inspectors will not be able to tell you how much tax you will have to pay by 31 January next year." Penalties will start to come into force after 31 January, including pounds 100 fines and surcharges. Mr Black also warned taxpayers not to panic and seek advice from disreputable firms. Tax advising is one of the few professions which is unregulated, Mr Black said, adding: "Taxpayers have no protection from `cowboy' firms."Reuse content