One Source and Capital Allowances

I've been completing my first 2012 computation for submission to HMRC.  One point to note is the way that OneSource deals with capital allowances.  At the foot of the capital allowances computation (schedule C6 in the computation I have been working on) there are two boxes to set the parameters for the WDA rate.  The first of these is a default rate set to 20% and the second is an "over - ride" rate.  If you leave OneSource as is it will use the default 20% rate to calculate capital allowances.  However, for an accounting period 1 January 2012 - 31 December 2012 the correct rate for writing down allowances is 18.49%. 

http://www.hmrc.gov.uk/budget-updates/autumn-tax/tiin1310.pdf)

To change the default rate to 18.49% you will need to enter this in to the "over - ride" cell.