The 34-year-old was sentenced to 16 weeks imprisonment, suspended for 12 months, and was also ordered to carry out unpaid work and pay £90 compensation.
Between October 2014 and March 2015, Thomas knocked on several elderly residents' doors asking to borrow money, police said. He created a fictional sob story to make the homeowners feel sorry for him.
He took the money from the residents but never paid it back.
In court, Thomas was also granted a Criminal Behaviour Order (CBO) - for three years - in which he cannot knock on any door in order to borrow money under pretence.
Thomas was arrested on March 8 and charged with six counts of theft on April 10, later pleading guilty in court, police added.
Speaking after the hearing, PC Hutchinson said: “This CBO will protect the community from his deceitful ways.
"The police are grateful for the support of the victims in this case to support the prosecution and the CBO which will prevent him from preying on the good-natured people of Harrow in future."