Taxpayers will fork out an annual $51,725 salary for John Key for the rest of his life, if he wants it.
The former Prime Minister is also entitled to a taxpayer-funded car that gets replaced every 60,000 kilometres, as well as free nationwide travel when he "carries out public duties".
The perks are part of remuneration provisions for former Prime Ministers and their spouses.
Mr Key's annual salary is known as an 'annuity' and is only paid to those who've held the top job for more than two years. It's also available to the surviving spouses of former Prime Ministers who have passed away.
The vehicle provisions are claimed to save the taxpayer money, despite having "considerable personal benefit".
"A former Prime Minister is likely to have to travel to and from airports and around the country in the course of commitments arising from his or her former role," The rules say.
"Use of a self-drive car is likely to be more cost effective than use of taxis or chauffeur-driven cars."
Both Mr Key and his wife Bronagh can also request a Crown limo for transport to events they attend as a result of their roles as Prime Minister and Prime Minister's spouse.
The same rule is applied to free domestic flights, trains, buses, and other forms of scheduled transport.
None of the perks are allowed to be used for personal or business benefit.
It's unknown whether Mr or Mrs Key will claim the entitlements.
Electoral law expert Graeme Edgeler told Newshub the rules seem reasonable as long as information about the spending is publicly available, however he was unsure about the new car policy.
"The annuity for former Prime Ministers is limited to people who've been Prime Minister for at least two years so the overall cost isn't great, and the funding of domestic travel they undertake as former Prime Ministers seems fair.
"Former Prime Ministers tend to have responsibilities that other former MPs and former ministers don't have, and are called upon to speak at public events and the like simply because they are former Prime Ministers. It seems reasonable for the taxpayer to fund this, given the public benefit, and as long as information about the cost of this travel is made available publicly.
"But giving former Prime Ministers a new car paid for out of taxes every 60,000kms seems a bit unnecessary. I would hope that most former Prime Ministers, especially those still working, would turn it down."
How other former Prime Ministers have been spending:
- Jim Bolger and spouse Joan spent over $100,000 between 2011 and 2014
- Dame Jenny Shipley and spouse Burton spent $70,687 over the same period
- Helen Clark and spouse Peter Davis spent $64,055 during that period