Increase in Petroleum Instalment Tax for 2025

After gathering updated figures from the oil companies, petroleum tax for 2025 was upwardly adjusted from NOK 336 billion to NOK 343 billion. This is equivalent to an increase of 2.1 percent. These figures represent a decrease from 2024 for which final petroleum tax amounted to NOK 382 billion.

Tax revenue from the extraction of non-renewable resources of oil and gas is deposited into the Government Pension Fund Abroad. Thus, the revenue benefits both present and future generations.

Instalment tax based on figures reported by the oil companies

Oil companies conducting extraction and pipeline transport on the Norwegian Continental shelf pay advance tax through so-called instalment tax. The instalment tax is payable in ten instalments, five in the fiscal year and five in the year following the fiscal year. Last summer, the combined assessment of instalment tax for the 2025 fiscal year amounted to NOK 336 billion. The assessment was based on figures reported by the oil companies in June 2025. The amount of the assessed instalment tax can be adjusted prior to the due date for the sixth instalment, 1 February in the year following the fiscal year. In connection with this, updated figures were obtained from the oil companies, resulting in an increase of the total instalment tax to NOK 343 billion.

Payment of instalment Tax

The oil companies have already paid NOK 169 billion for the first, second, third, fourth and fifth term in the second half of 2025. NOK 174 billion of the petroleum tax for the 2025 fiscal year remains to be paid. This amount will be paid in five instalments during the first half of 2026.

The amount, including interest, due for payment in the sixth, seventh, eight, nineth and tenth instalment has been assessed by the Oil Taxation Office as follows:

* The companies have an option to make a higher payment than the assessed amount along with the seventh/eight/ninth instalment. The actual/final amount paid may consequently be higher.

Assessment of Instalment Tax 

Oil companies conducting extraction and pipeline transport on the Norwegian Continental shelf pay advance tax through so-called instalment tax. The instalment tax is paid in ten instalments - five in the second half of the fiscal year and five in the first half of the year following the fiscal year. The assessment is based on figures (both actual and expected/estimated) reported by the oil companies. 

A revision of the instalment tax is taking place in January of the year following the fiscal year, prior to the deadline for the sixth instalment. The companies have an option to make additional payments to the assessed amounts with their second/third/fourth and seventh/eighth/ninth instalments respectively. The final payment may therefore end up higher than the present assessment. 

Facts About Instalment Tax

• The Petroleum Taxation Act has a special advance tax scheme named instalment tax, according to section 7 of the Petroleum Taxation Act. 
• Instalment tax is assessed by the Oil Taxation Office for each fiscal year and is payable in ten instalments, five in the fiscal year and five in the year following the fiscal year. 
• The instalment tax for each fiscal year is assessed in June/July in the fiscal year. The assessment is based on information obtained from the companies and consists of actual figures for parts of the first six months and estimates for the rest of the year. 
• The Oil Taxation Office may revise the instalment tax prior to the payment deadline of the sixth instalment. This revision is based on actual figures for most of the fiscal year. 
• The deadlines for payment of instalment tax are respectively 1 August, 1 September, 1 October, 1 November and 1 December in the fiscal year, and 1 February, 1 March, 1 April, 2 May and 1 June in the year following the fiscal year. 
• The companies have an option to make payments larger than the assessed amounts with their second/third/fourth and seventh/eighth/ninth instalments respectively if they consider their original estimates to be too low. 
• Interest is calculated when there is a discrepancy between the instalment tax for the first five instalments and the final five instalments. 
• The tax assessment for any given fiscal year is due on 1 December of the year following the fiscal year. There will be a reconciliation between the assessed tax/tax refund and the instalment tax. 

More information about petroleum tax.