The Australian Taxation Office (ATO) says it has come to a confidential settlement worth $157 million with petrol giant Ampol over its Singapore tax hub.

Ampol said in a statement that it will pay a further $5.6 million in Australian tax on earnings between 2014 and 2021, and $0.1m in interest.

This is in addition to the $104.1 million of tax already paid on Ampol Singapore earnings.

In June 2023 Ampol will pay $48.2 million in Australian tax on Ampol Singapore earnings in the 2022 financial year.

Ampol has written back excess current tax liabilities and deferred tax assets recognised between 2014 and 2022 in accounting for the full amount in dispute, with this write-back resulting in a one-off benefit to corporate tax expense in 2022 of $110.2 million, recognised as a 'significant item'.

No penalties have been imposed on Ampol, and the ATO has not applied any anti-avoidance provisions.

ATO deputy commissioner Rebecca Saint said the settlement also "locks in" the company's tax arrangements out to 2033.

"Locking in tax outcomes for the future has become an important feature of our settlements with multinationals as it provides us, taxpayers and the community with certainty that the multinational is meeting their tax obligations into the future, avoiding future disputes," Ms Saint said.

The ATO's Tax Avoidance Taskforce has had a focus on offshore procurement hubs for a number of years.

The hub is used to procure goods from third party suppliers and in turn on-sell those goods to the Australian arm of the group and is typically located in a low or no tax jurisdiction.

"We are keen to ensure that procurement hubs are not used as a mechanism to shift profit from Australia by charging excessive prices for imported goods and services in an effort to reduce tax paid in Australia," Ms Saint said.

The ATO says since the Taskforce's inception to date it has raised tax liabilities of $18.7 billion, although it has previously said some of the tax bills issued are being disputed.

She noted details of the settlement are confidential and comes after the ATO has reached settlements in previous years with other companies including Rio Tinto, Google, BHP, Apple, ResMed, and Microsoft.

Ampol group chief financial officer Greg Barnes said Ampol approached the ATO in 2014 in relation to its operations in Singapore.

"We are pleased to have reached an agreement with the ATO and to have certainty over the future tax treatment of Ampol Singapore earnings. The changes minimise operational disruption, while ensuring we fairly meet our tax obligations in Australia."