These include claims under the £ 24,000-a-year additional costs allowance , which reimburses MPs for the cost of having to maintain a second home while serving at Westminster ; the £ 22,000 incidental expenses provision , which pays for running an office ; and the £ 10,400 communications allowance , which covers the cost of newsletters and websites to inform constituents about their activities , as well as details of expenditure on stationery and postage .