Those running a business should take advantage of the temporary increase in the Annual Investment Allowance (AIA) to £250,000.  5th April 2014 is not relevant for this tax break as the limit continues until 31 December 2014, although there are complex transitional rules. AIA provides a 100% tax write off for plant and equipment used in your business. This tax relief extends to fixtures and fittings within business premises such as electrical, water and heating systems.