Paul Lawrence and Natasha Moxey were both convicted by a Gloucester Crown Court jury of six charges and bailed for pre-sentence reports.
Judge Michael Cullum told the pair "There is an overwhelming likelihood that both of you will receive significant immediate custodial sentences."
They will return to court for sentence on May 26.
The pair had denied all the allegations against them but did not give evidence on their own behalf during their two week trial. They simply made speeches to the jury at the end of the prosecution case but did not go on oath or face cross-examination by prosecutor Mark Hollier.
Lawrence, 62, and Moxey, 31, of of Brown Close, Hester's Way, Cheltenham, had both pleaded not guilty to:
- Conspiring to pass or tender counterfeit currency between 15 June and 5 July 2012
- Two offences of dealing in or harbouring cigarettes and tobacco with fraudulent intent on 10th Sept 2012 and 3 July 2913
- Fraudulently claiming at least £34,249 in housing benefit and council tax between 1 May 2008 and 10 June 2013
- Fraudulently claiming employment support allowance of at least £10,438 between 1 Jan 2011 and 10 July 2013
- Defrauding the DWP of at least £10,950 in disability living allowance between Nov 2010 and Jily 2013 by claiming Lawrence suffered to greater disability than he did.
- After a day and a half of deliberation the jury convicted them unanimously of four of the charges and by a majority of 11-1 on the remaining two charges.
She worked as a cashier in the Farm Foods shop in Coronation Square, Cheltenham, and accepted counterfeit currency from the pair, giving them genuine money as change when they used the fake £20 notes to pay for small items.
The shop scam was rumbled by managers who watched CCTV footage of the £20 exchanges.
Police then went to the couple's home and found 7,200 duty free cigarettes and 15.2 kilos of rolling tobacco.
Officers also discovered that Lawrence had £90,000 in an offshore Lloyds TSB account in Jersey - but he and Moxey were claiming housing and council tax benefits as well as employment support allowances, Mr Hollier said. They were not entitled to those benefits because they had more than £16,000 in capital.
Also, Lawrence had been receiving disability living allowance even though he had no visible disabilites or problems, Mr Hollier added.
When police later went to their home with council and Dept of Work and Pensions investigators another batch of duty free tobacco weighing 4.10 kilos was found.
The couple both declined to answer any questions when they were arrested.
"Mr Lawrence had been receiving the highest level of care and mobility allowances," said Mr Hollier. "All the evidence we have about him is that he is fine. "
In evidence Miss Oakley confirmed that she took the forged notes from her 'auntie' Natasha and Lawrence and said she was paid with tobacco for her services.
She said she had not realised at first that the couple were giving her forged notes but then she 'clocked' what was going on and went along with it.
She has pleaded guilty to involvement in the currency scam and will be sentenced together with Lawrence and Moxey later this month.