The new 12-sided pound coin will cost the council £79,000 in adaptations to all its pay parking machines.
This week MK Council said it had “no choice” but to go ahead and pay for the necessary work.
“This is money we’d rather be spending on things like public transport,” said a council spokesman.
The cost will not be refunded by central government, who voted in the change in a bid to combat fraud.
There is speculation that tens of thousands of parking machines will not be ready in time to accept the new coin, which are due to enter circulation on March 28.
But Milton Keynes Council is determined to be not to be caught out on the big day.
The spokesman said: “Many places have been criticised for not being ready in time, but we have made sure we are prepared for day one.”
He added: “Sadly that comes at a cost we did not ask for.”
Pay and display parking raked in £13m for MK Council last year.
The parking charges themselves account for a hefty £9m, while parking permits generated a £3m income.
Another £829,000 came from penalty charge notices and excess charges paid by the public.
The council spent almost £2.5m on expenses, including management fees for contractors, parking meter installation costs and staffing.
The profit they pocketed was just under £11m.
Though there is a swing towards paying for parking online or via mobile phones – particularly at CMK – many people still save up pound coins for the meters,
The new coins, which resemble an old-fashioned threepenny piece, will be in circulation for six months before the old pound coins are phased out in October this year.
So far the Royal Mint had withdrawn 50 million of the round pounds, representing three per cent of the total in circulation around the UK.