More than 1 million vouchers were redeemed on the final day of the NSW government's Dine and Discover program, but close to 9.5 million vouchers expired without being used.

The government spent $550 million on the scheme, which offered residents $25 vouchers for dining and entertainment venues to encourage spending after COVID-19 lockdowns.

Customer Service Minister Victor Dominello said on average about 45,000 vouchers had been used each day since the program started in March 2021.

But those who had forgotten to use their remaining vouchers spent big on Thursday night, with 1,118,964 vouchers redeemed on the final day — amounting to a spend of $38,017,863.

"I think it shows that people are busy with their lives," Mr Dominello said.

"The fact they were easy to use meant there was a big rush towards the end."

The state's Opposition has been calling for an extension to the economic stimulus but the Minister has remained firm against the idea, saying the $230 million in unspent vouchers would be returned to state coffers.

"That money simply goes back into consolidated revenue.

"Not everybody wanted to enjoy the benefits of the vouchers, in fact one in every 10 adults in NSW chose not to. But the reality is nine out of 10 chose to."

Despite being responsible for overseeing the program, Mr Dominello also took part in the last-minute dash to spend his vouchers.

"I rushed to my local Thai shop and I was told that he had to employ another person just to deal with the demand on the last day, so that's a good problem to have," he said.

The scheme encouraged people to spend an additional $350 million on top of the contribution made by the government.

"And that doesn't include indirect spend, for example the taxi to the venue or a gelato after the event," Mr Dominello said.

"The indirect spend would have easily meant that the total injection into the economy was well over a billion dollars."

The Service NSW smartphone app still has vouchers available for parents, swimming lessons and before and after school care.