Research and development tax credits allow companies to claim enhanced tax relief in the U.K. for qualifying R&D spending. Their aim is to encourage U.K. R&D and to promote investment in innovation. In the Budget 2004, changes were introduced aimed at simplifying the definition of R&D and widening the range of expenditure that will qualify for R&D tax credits. These represent a further government investment in R&D worth £35 million per year.