On 30 June 2011 Josie Jones, aged 42, ceased self-employment as a graphic designer. On 1 August 2011 she commenced employment with Typo plc as a creative director. The following information is available for the tax year 2011–12:

Self-employment
(2) The tax written down value of the capital allowances main pool at 1 May 2010 was £13,200. On 21 May 2011 Josie purchased computer equipment for £3,600. All of the items included in the main pool were sold for £7,700 on 30 June 2011, with no item being sold for more than its original cost.

Required:
What is the balancing allowance / charge for the final period?

The capital allowances for the year ended 30 April 2011 are 2,640.