A former Napier couple who lied to get benefits they were not entitled to have been sentenced to five months' community detention.

Chelsea Hibben, 31, and Mathew John Roberts, 33, were sentenced in the Napier District Court yesterday after earlier admitting benefit fraud totalling more than $36,000.

Chelsea Hibben leaving the Napier District Court.

The pair were living in a de facto relationship between October 2014 and February 2017, when Hibben was receiving a sole parent support benefit.

The mother-of-two didn't tell the Ministry of Social Development about her change in circumstance and claimed she was not living in a relationship with anyone, did not have a partner or that Roberts was her boarder.

As a result, she continued to receive the sole parent benefit, accommodation supplement and temporary additional support.

In July 2015, Roberts submitted a Jobseeker Support Application form stating he was single, did not have a partner and was boarding at a Napier house and paying $160 a week to "Chelsea Lewis".

That same day Hibben submitted a supporting letter under the name Chelsea Lewis, confirming Roberts was a boarder. As a result, he received the jobseeker support benefit and accommodation supplement at the single rate.

The pair separated in February last year, after which Hibben was interviewed about her letter and said she was aware of her obligations but hadn't told the ministry because she knew the benefit would stop.

Roberts also said he knew of the benefit fraud and didn't declare he was living with his partner so he could get the single rate of benefit.

He was jointly liable for overpayments totalling $36,580.19.

The couple had used the money to pay joint or household expenses, the summary of facts read.

Hibben pleaded guilty to benefit fraud and nine charges of using a document to obtain a pecuniary advantage. Roberts pleaded guilty to one charge of benefit fraud and three of using a document.

At sentencing on Thursday, Hibben's lawyer, Cam Robertson, said her reasons for offending, personal circumstances and early guilty plea meant an electronically monitored sentence was appropriate.

Roberts' lawyer, Nigel Hewitt, said his client was the "lesser offender" and had a full-time job so could continue repayments.

MSD prosecutor Paul Frost said Hibben was stil a beneficiary so reparation was not sought, but it would seek reparation from Roberts for half of the full amount owed.

Judge Bridget Mackintosh said the amount of money was not insignificant but added both defendants came well within the range for electronically monitored sentences.

"Benefit fraud is a serious offence.

"Of course, it involves a breach of trust because it is the taxpayers that are paying the benefits and, of course, if you're telling lies you get money you're not entitled to; money that is hard-earned by members of the community."

She sentenced both defendants to five months' community detention, with curfews of 6pm to 6am Monday to Sunday, and also imposed nine months of supervision on Hibben and 80 hours of community work on Roberts.