Corporate - Tax administration

Last reviewed - 23 January 2024

Taxable period

The income tax year normally runs from 1 January to 31 December, with assessments being issued no later than 1 December in the following calendar year. Companies are liable for both advance payments and final settlements in the calendar year of assessment. Companies with a financial year other than the calendar year may use the financial year for tax purposes in certain instances (e.g. if they belong to a foreign group with a deviating accounting year, they may also use the financial year of the group for tax purposes).

Tax returns

Companies are, in general, required to file their tax returns electronically by the end of May in the year following their financial year. Upon application, an extension until the end of June to file the tax return will normally be granted. The tax returns and the basic attachments are obligatory for all corporate taxpayers. Additional requirements may apply for specific business sectors, such as hydro power production. Under the petroleum tax regime, the filing deadline is the end of April.

The taxpayer is responsible for reporting the taxable income in the tax return, which will be the basis for the tax assessment. The taxpayer can voluntarily change information given in the tax return for up to three years after submitting. This does not apply to the income years prior to 2017, where an appeal must be filed in order to amend the tax assessment.

Payment of tax

Companies are required to make advance payments of tax on 15 February and 15 April in the year following the income year. The two payments should together cover all of the expected CIT to be assessed but could be complemented by an additional payment by 31 May of the year following the income year to avoid interest on any remaining tax balance. If the remaining tax balance is not paid by 31 May of the year following the income year, the company will receive an invoice from the tax authorities that is due for payment three weeks after the assessment has been made public (i.e. in September/October of the year following the relevant accounting year).

The above applies to all corporate taxpayers, except for taxpayers under the petroleum tax regime, where tax shall be paid in six instalments.

Tax audit process

The Norwegian tax system is tax return based. The Norwegian tax office carries out tax audits based on different selection criterions. A tax audit can be caused by a review of the tax return, random selection of companies or business sectors, information obtained from other parties, etc.

The tax office normally gives notice of an upcoming tax audit, but it can also be unannounced. The examination generally takes place by formal, written communication, and the process can take from a few weeks to several years.

In general, a reassessment of the tax assessment requires a notice from the tax authorities with a reasonable timeframe for the taxpayer to give a reply to the notified amendments.

Statute of limitations

The general reassessment period is five years (starting from the year after the income year in question). A ten-year limit applies in cases where the taxpayer has demonstrated gross negligence. The reassessment period will apply to the income year 2015 going forward. For the years 2013 and 2014, the old reassessment period will, in general, apply to the advantage of the taxpayer (see below).

After the old statutes of limitations, the tax office has a ten-year limit for reassessing tax assessment (from the year after the income year in question). However, a two-year limit applies for negative adjustments and a three-year limit for positive adjustments if the taxpayer has provided sufficient and correct information in the tax return.

The taxpayer may file an appeal on the resolutions made by the tax authorities within six weeks after they were sent to the taxpayer. The time limit for appealing other decisions is normally three weeks after the tax office’s decision. This applies both under the new and previous rule set.

Topics of focus for tax authorities

The tax office’s topics of focus can vary each year and from region to region. The primary topics of focus lately have been interest limitation, transfer pricing, and (cross-border) reorganisations.