According to the accountancy and business advisory firm BDO (www.bdo.global), HMRC estimates that businesses have incorrectly claimed R&D tax reliefs amounting to £612 million.

This high level of ‘tax under consideration’ suggests that businesses should be more cautious when claiming R&D tax reliefs to avoid unnecessary — and potentially expensive — tax disputes.

R&D tax credits are worth more than £4.3 billion to UK businesses, and BDO says that this is one of the most generous tax breaks that UK businesses can benefit from.

Eyad Hamouieh, a partner at BDO, said: “HMRC’s tough stance on the mis-use and over-claiming of R&D tax credits will no doubt become an area of increased focus.

“That said, while some businesses are getting into a fix by over-claiming, many more businesses are failing to claim the money they are entitled to.”

HMRC is also targeting businesses for £90 million in underpaid tax relating to Patent Box in 2018/19 — up 15% from £78 million in 2017/18.

Patent Box allows companies to pay tax at an ‘effective rate’ of 10% on patent-related profits, as opposed to the standard 19% rate of corporation tax.

BDO says identifying the profits that result directly from a patent can be confusing, leading to businesses over-claiming the Patent Box relief.

One problem has been the growth in unregulated ‘tax boutiques’ offering advice to businesses on how to maximise their tax rebates.