Students and single people across Brighton and Hove face a knock at the door from council tax revenue inspectors.
Jason Kitcat, the Brighton and Hove City Council cabinet member for finance, said that the inspectors would carry out a thousand checks in the coming month.
The move comes as part of a drive to make up a £1.1 million shortfall in council tax revenues.
A report to the city’s cabinet said that people were paying their bills on time.
But, it said, more discounts were being awarded to people who lived alone.
And more students were claiming their council tax exemptions – with a further rise expected as the autumn term gets under way.
A growing number of landlords were also claiming exemptions for empty properties during the summer holidays.
The same report said that the council was on course to overspend by £1.3 million in the current financial year from its general fund.
It added that there was a risk of a shortfall in “value for money” savings of about £1.8 million, adding to the financial pressures faced by the Green Party administration.
Councillor Kitcat said that savings made in previous years could be compared to “low-hanging fruit” but the savings being targeted in the current financial year were harder to achieve.
His comments were made as Andrew Stunell, the Liberal Democrat Housing and Regeneration Minister, said that the coalition government would bring in an empty homes tax.
The tax would allow councils to charge a premium if owners left homes empty for more than two years.
The aim was to reduce the huge number of empty properties at a time when councils still have long waiting lists.
Nationally, he said, 700,000 homes were empty, with more than 300,000 having been vacant for longer than six months.
In Brighton and Hove more than 3,600 homes are empty, many because they are being refurbished or the owners are away or in care.
But the council said that it was not aware of a good reason for nearly 1,000 of the homes being empty.