Kay Maxwell, 37, of Mons Avenue, Hebburn, was a Her Majesty's Revenue and Customs (HMRC) contact centre advisor in Newcastle and claimed to be living alone with her two children.
She was arrested in December 2016 after investigators found she was living with her partner and had provided false information to HMRC.
Maxwell, who was a HMRC employee for 13 years until her dismissal in February 2017, fraudulently claimed £43,631 in tax credits between 2011 and 2016.
She had two further children during this period but did not claim tax credits for them.
Maxwell admitted tax credits fraud at South Tyneside Magistrates’ Court a month ago and appeared for sentencing at Newcastle Crown Court this week.
She was sentenced to 12 months in prison, suspended for 18 months, with 20 days' rehabilitation activity and 125 hours unpaid work at Newcastle Crown Court by Judge Tim Gittins.
Proceedings are underway to recover the stolen money.
Joff Parsons, assistant director of internal governance at HMRC, said: “Maxwell knew what she was doing was wrong and thought she could get away with stealing tax credits she was not entitled to. But her deceit was exposed and now she is paying the price.
“We expect the highest professional standards and integrity from our staff; no one is exempt and we will pursue criminals like Maxwell who think it is acceptable to steal tax credits. We ask anyone with information about tax fraud to contact the HMRC Fraud Hotline on 0800 788 887.”