Peter Childs and his wife Alison took the disability living allowance benefit money and cold weather payments paid out to people with learning disabilities who were supposed to be assisted by Lincoln and District Mencap.
At the time Peter Childs was chairman of the charity and his wife was employed as accommodation manager.
A jury at Lincoln Crown Court heard how the couple also overcharged the clients for utility bills stole their life savings.
During a five week trial the jury was told that they had defrauded clients of Lincoln and District Mencap over a six year period taking over £200,000 by exploiting their victims’ vulnerabilities.
Peter Childs later suffered a stroke which left him confined to a wheelchair. It was only then that the irregularities came to light.
Mr Lowne said the most significant case of overcharging involved twin brothers Roger and Richard Fogg, 57, who between them paid £28,000 towards their gas, electricity and water when the bills on the property they shared came to only £7,400.
In addition Richard handed over £7,300 savings together with £6,900 from his Disability Living Allowance and £275 in Cold Weather Payments. Roger paid over identical amounts of DLA and Cold Weather Payments as well as £5,846 in savings.
During a five week trial the jury heard how bogus annual accounts were submitted for the charity. These were signed in the name of a bank official who had died a number of years earlier.
Peter Childs,61, and Alison Childs,48, of Hall Lane, Nettleham, were each convicted by a jury of 12 charges of theft and 14 charges of fraud by abuse of position between December 2005 and December 2011. Alison Childs was found guilty of a further fraud charge. They had denied the charges. Peter Childs had previously admitted two charges of fraud. They were each cleared of a further charge of theft.
Judge Sean Morris adjourned sentence until later this year and granted both of them bail. But he warned them: “A prison sentence is inevitable. It is a question of how long.”