Yateley Industries is a near 90-year-old charity in Hampshire that employs almost 60 people, most of whom have disabilities, in a range of packaging jobs.
It says it is owed £186,000 by the Access to Work scheme.
"It's an existential threat to us," says chief executive, Sheldon McMullan. "If we don't get it, we could potentially close this magical place forever, and that would be a tragedy for the local community and for the government's agenda more broadly."
Yateley Industries is part of a nationwide forum of dozens of supported businesses - companies specialising in employing disabled people.
Mr McMullan says many others are affected by the backlog.
"The annoying thing is that it's money that's been granted to us," he adds. "We have the paperwork saying this is what each person's been awarded, but the claim system is not set up for us to draw down the money effectively."
Businesses say that as well as poor internal processes at the Department for Work and Pensions, there has also been a large increase in the bureaucracy associated with Access to Work in recent months, with many more forms having to be filled in and then posted – not uploaded or emailed – to the DWP.
"Until ministers realise that they've got this wrong, they're in danger of pushing so many disabled people out of the workplace," says Steven McGurk, president of the trade union, Community Union.
"Its very bureaucratic, very difficult to claim - it's the biggest threat to disabled people's employment."