Deadlines for change
You can make changes for up to three years after the original deadline for submission of the tax return for VAT. This applies when the change is in favour of the enterprise. When the change is not in favour of the enterprise, it is your obligation to make the correction. This obligation applies for a period of ten years.
Errors in customs declarations
If you discover errors in a customs declaration, you must submit an application for recalculation to Norwegian Customs. Changes to a customs declaration can often result in changes to VAT. In such cases, you must also submit a correction (tax return for VAT) for the period covering the date of the original customs declaration.