Most of the MPs allowances are paid by the House of Commons directly in salaries to the staff who work in constituency offices, or to pay for things like office bills and stationary through the Incidental Expenses Provision (IEP).
In addition, the Additional Costs Allowance (ACA) was set up 30 years ago because MPs from outside London need to be able to live in their constituencies and also be in Westminster for debates and votes. MPs can only use the allowance for a second home and must, of course, pay all the bills on their main home themselves. It reflects the fact that average private rents for two bedroom flats in Westminster are around £15,000 a year. New rules and independent audits are already in place for this housing allowance, and I’m backing further reform too. | 
