Voluntary disclosures of tax return carelessness could now attract a 10 per cent penalty, experts have suggested, after the tax office changed its penalty factsheets just before Christmas.
In the past, voluntary disclosures of tax errors that were made carelessly did not attract a penalty, but the new wording on the factsheet published by HM Revenue & Customs suggests this is no longer the case, accountancy firm RSM has warned.
The factsheets now contain wording suggesting those who take a long time to notice an error will be penalised.
The factsheet stated: "If you have taken a significant period (normally three years) to correct or disclose the inaccuracy we will normally restrict the amount of reduction given for disclosure.
"We will restrict the penalty range by 10 percentage points above the minimum to reflect the time taken before working out the reductions for telling, helping and giving."
A spokesman for the accountancy firm said the new approach "might well have the effect of encouraging individuals not to make a disclosure and hope that they can remain beneath the radar."
There is an urgent need for HMRC to clarify exactly what their policy now is, to confirm its legal basis, and to explain why they believe this overturning of such a long-standing principle is necessary, the RSM spokesman added.
According to tax factsheets, HMRC's penalties for carelessness should not apply if it was found you took reasonable care but still made an error.
Some examples of taking reasonable care include keeping enough records to make accurate tax returns, keeping those records safe, asking HMRC or a tax adviser if you are not sure about anything, and following any advice you are given.
Martin Bamford, managing director of financial advice firm Informed Choice, said the change in stance from HMRC "hints at the Treasury getting quite desperate for cash, which we know that they are."
He said: "However, it is important for people to take reasonable steps to get their tax returns right, and if that means preparing them a bit earlier and involving an accountant then this may save money in the long run."
HMRC has been contacted for comment.