Tenants are being encouraged to attend a property swap event next week.
From April 1, working age tenants living in homes with spare bedrooms face having their housing benefit reduced.
The amount people can claim is based on the number of bedrooms needed by the household rather than the number of them in the property.
One spare room means an average reduction of £16 a week; two or more rooms mean an average reduction of £30 a week.
Around 1,400 council tenants are currently living in under-occupied homes and will be affected by the benefit changes.
Councillor Dudley Mead, cabinet member for housing, said: “The property swap pilot in New Addington was a great success, and we are looking to build on that with our borough-wide event at the Fairfield Halls.
“We don’t want people to lose money when the benefit changes come in, so if you have any spare bedrooms, we urge residents to attend this event and consider downsizing to a more suitably sized home.”
The property swap event is taking place on March 5, 12-5pm, at Fairfield Halls. For more information visit croydon.gov.uk/benefitchanges or call 020 8726 6100.