The bill for MPs' expenses and offices rose by 1.6% to nearly £106 million last year, according to new figures.
Staffing costs went up by £2.2 million to £82.7 million, but spending on flats, hotels, travel and subsistence was down around £150,000 at £11.6 million. The amount laid out on renting and equipping offices was £10.7 million.
The overall increase between 2013-14 and 2014-15 was the slowest in recent years, and could indicate that many MPs were winding down their activities ahead of the general election.
The Independent Parliamentary Standards Authority (Ipsa) is due to release a full breakdown of each MP's claims and salary costs later. The figures cover the period before the controversial 10% pay rise was implemented.
For the first time the watchdog will "name and shame" 26 MPs who refused to settle debts totalling £2,105.43 last year, forcing the sums to be written off.
Details of politicians' landlords will be published, along with the job titles of all staff employed. Last year MPs had 4,021 staff on the books - compared with fewer than 3,000 in 2009-10.
Ipsa chief executive Marcial Boo said: "Our regular publications include every single penny claimed by MPs, so that taxpayers and voters can see for themselves how their money is spent and gain assurance that Ipsa is scrutinising MPs' expenditure on their behalf."
Jonathan Isaby, chief executive of the TaxPayers' Alliance, said: "MPs clearly need a properly-resourced office to help them carry out their parliamentary and constituency duties, although they must always seek to achieve value for the taxpayers' money they are spending.
"At first glance, these latest figures are to be welcomed since MPs appear to have kept costs under control, effectively reducing the total spent on running their offices after inflation is taken in to account.
"It remains a matter of concern that Ipsa has had to write off debts amounting to more than £2,000.
"If the expenses scandal taught MPs anything, it should be that the public expect the very highest standards of probity and integrity when it comes to making claims on the taxpayer.
"Any of the MPs or living former MPs still owing money to the authorities should pay what is due immediately."