Expenses, a word which makes many a constituent grumble. When an MP is elected, the work they do is paid for by the tax payer. The expenses system allows an MP to cover their day to day business costs and expenses.
This is overseen by an independent body called the Independent Parliamentary Standard's Authority - IPSA. Every two months IPSA publishes individual claims made by MPs and keeps details of their annual costs. There are limits to these budgets and these do change depending on whether you are an MP for London or for other parts of the United Kingdom.
All MPs are expected to work Monday to Thursdays in Westminster and so accommodation and travel to London is supported under the MPs expenses scheme. Similarly if MPs have a late sitting, they can apply for additional food and drink or an overnight hotel stay/taxi ride. However again there are caps and every receipt put forward is reviewed.
There is a similar scheme in place for the Lords.
The days of MPs ordering duck houses for their second homes or for staff to clear their moats are long gone, but rumours about expenses linger. The majority of my expenses go towards running my two offices (Tamworth and Westminster).
You can find the details of spending related to my office online at https://www.theipsa.org.uk/mp-costs/your-mp/chris-pincher/
IPSA also hold details on MP's pay, payments MPs receive from other work (I do not work a second job) and register of interests for any gifts received.