BERNESLAI Homes is expecting to face up to several million in rent arrears when the new Universal Credit benefit is introduced in Barnsley.
Director of housing management at Berneslai Homes, Mark McGee, revealed the figure at a Barnsley Council watchdog meeting.
He was asked by Cllr Joe Hayward what the cost will be to Berneslai Homes when Universal Credit comes into force, replacing six existing benefits, including jobseeker's allowance, employment and support allowance, income support, working tax credit, child tax credit and housing benefit.
The change means claimants will be paid their total benefits monthly, rather than weekly, and they will be responsible for paying their own rent, rather than it being deducted from their benefit.
Mr McGee said it's the single biggest risk 'without a doubt'.
Universal Credit will be introduced in pilot areas from this month, but it will be brought in across the regions in stages, with it expected to be brought in in Barnsley in 2015.
"There's a tremendous amount of work to do to make sure people know they will have to pay their rent," said Mr McGee.
"The cost to Berneslai Homes? If everybody paid their rent it would still cost us hundreds of thousands of pounds to collect the money.
"That will not happen. We're talking about several million being lost in rent arrears."
Peter Francis, from the Welfare Rights Service, said he thinks people know the name 'Universal Credit' but not what it involves.
"Under Universal Credit there will have to be a new regime of sanctions, much more stricter than ones we are used to," he warned.
"We will see people losing benefits for three weeks to years for serious offences.
"A lot of people will suffer short-term sanctions for four weeks if they fail in their claims, such as failing to turn up for an appointment or signing-on day, there can be all sorts of reasons.
"Other bits about Universal Credit is people will have to be available and seeking work 35 hours a week and that's a huge change. They will have to claim on line and not everyone can.
"People aren't prepared yet. It's the next wave to hit us and there is an awful lot still to be done."