The scheme for large companies is called the R&D Expenditure Credit (RDEC) and operates in a different way to that for SMEs. It is essentially a taxable grant, currently 13% (12% before 1 April 2020) of qualifying expenditure.
In most cases it can be offset against corporation tax but large companies without taxable profits can claim it as a cash payment, net of a ‘withholding tax’ at the same rate as corporation tax too.