And if you have unclaimed Medical expenses for previous years you can claim back 4 years. (2007,2006,2005,&2004)
Simply send copy of P60 for the relevant years together completed form Med 1. Make sure you have receipts for all expenses claimed which you are required to keep and may be asked to present in case of query. When you receive 2008 P60 process your claim for the current year.
Relief will given at your Marginal rate of tax.
All that changes in 2009 when relief will be at 20%