Adeola Thomas, 38, an illegal immigrant living in Hackney, north London, ran a scam that involved filling out more than 2,000 claim forms by hand, Her Majesty's Revenue and Customs (HMRC) said.
He managed to get £87,000 paid out but was caught when benefits staff noticed the same address for multiple claims.
Thomas was arrested at a cash point in October last year while under surveillance by teams from HMRC. He had 17 Post Office account cards in different names.
The Nigerian was helped by his partner Abimbola Abiola, 34, and the pair stole more than 1,400 identities to complete 2,495 claim forms for tax credits and benefits.
Thomas spent his share of the money on designer clothes, while Abiola treated herself to a 50-inch television.
Investigators believe they had help from other people who have not yet been identified.
The pair were jailed at Snaresbrook Crown Court yesterday, with Abiola being sentenced to two and a half years.
When she was arrested in October last year, she had £4,125 in cash in her handbag, which she claimed was child benefit - despite the fact she only had one child.
Thomas was imprisoned after admitting conspiracy to defraud and money laundering, while Abiola was found guilty of conspiracy to defraud, money laundering and possession of criminal property.
They will be deported after serving their sentences.
Passing sentence yesterday Judge William Kennedy said: "This was no less than a criminal industry, with simple and eye-watering criminality designed to maximise the loss to the public."
Simon De Kayne from HMRC said: "Adeola Thomas was the mastermind behind this fraud. He and his partner tried to rob the UK of vast sums of public money.
"They used the stolen identities of innocent people in an attempt to claim funds they weren't entitled to."
