The first £600 energy payment vouchers will start arriving with households from 16 January, it has been confirmed.
The process is expected to take four weeks and the vouchers can only be redeemed at Post Offices.
Every household is set to receive £600 from the British government as an alternative to the scheme operating in Britain.
It had already been announced that people who pay for their energy by direct debit will receive the money directly into their bank accounts.
Those without direct debits will receive a voucher for £600 that they can redeem at a post office.
People have been advised to redeem the voucher soon after getting it to ensure post office branches have enough cash.
Mark Gibson, external affairs manager at Post Office NI, told the BBC that those highlighted by energy firms as the most financially vulnerable customers will receive payments in the first phase.
Mr Gibson said: "We are asking customers, for security reasons more than anything else, is that they would immediately deposit that cash into their bank account which they can do at every Post Office in Northern Ireland."
He said the Post Office and energy suppliers will not be sending out texts and emails or calling customers ahead of the scheme but would "simply receive this voucher and this letter".
In order to redeem the voucher, customers will need to bring the letter from their energy supplier, the voucher, proof of address and a photographic ID.
Keypad customers will also need to bring their top-up card or app.
The government had estimated around 500,000 households will receive the money, which would mean a total of approximately £300 million. However, the number of private households in the north was 768,900 at the last census meaning the cost could be closer to £500m.
The one-off £600 payment includes £400 as part of a UK-wide support scheme and an additional £200 in recognition of Northern Ireland’s dependence on home heating oil.
Energy customers elsewhere in the UK have already begun to receive support payments.
The roll-out in Northern Ireland was delayed, with the government citing the lack of powersharing executive at Stormont as a major factor in the hold-up.
