Analysis by TaxWatch found that over half of the Patent Box tax relief went to just 10 companies in the 2022-23 tax year, while 41% of the payout went to just five large businesses, representing around half of the total £1bn annual tax relief, revealed data from a Freedom of Information request to HMRC.

One of the biggest beneficiaries over the years has been pharmaceutical giant GlaxoSmithKline (GSK) which has claimed 27% of all Patent Box relief since it was first  introduction in 2013 – and in some years close to 40%, TaxWatch reported after analysis of annual reports and accounts.

Official figures showed that HMRC granted tax relief using Patent Box to 1,630 companies totalling £1.97bn a year in the 2023-24 tax year. The scheme allows qualifying companies to pay 10% corporation tax on profits from patented products instead of the current headline rate of 25%.