A former MP has taken $9000 in travel perks he was not entitled to after a blunder by the Parliamentary Service.

The service's annual report has revealed it incorrectly advised an ex-MP he was entitled to the perk. He claimed $9000 in domestic and international travel for himself and his spouse before the service belatedly realised he had not served the minimum time in Parliament to qualify.

MPs must have served more than three terms, and only those elected before the 1999 election qualify for it.

The Parliamentary Service funds the running costs of MPs, including their offices, travel, salaries and other allowances.

It is unclear who the ex-politician is - the service is not open to public scrutiny because it is exempt from the Official Information Act.

A spokesman said the service would not release the name of the former MP or the circumstances under which its error was made. It does not appear the politician was asked to repay the money.

Former MPs who served three terms get a 60 per cent discount on 12 return domestic flights and about $11,000 worth of international travel each year. Those who served four terms get a 75 per cent rebate and those with five terms get 90 per cent.

Speaker Lockwood Smith has recently reinstated a "freeze" on the entitlement so that the last batch of MPs who qualify for it - those elected in 1996 - will not be able to claim more than 75 per cent when they leave Parliament.

Although the currently unlimited travel entitlements of sitting MPs are being overhauled, a recent review of politicians' perks and allowances recommended that no changes be made to the entitlements for former MPs because they no longer applied for incoming MPs and would eventually phase out.