After a tax return is final, the Dutch tax authorities can, in certain situations, still impose an additional tax assessment if too little tax is levied. In domestic situations an additional tax assessment can be imposed up to 5 years after the end of the tax year plus the period of extension granted for filing the tax return. In case of non-domestic situations an additional tax assessment can be imposed up to 12 years after the end of the tax year plus the period of extension granted.

In the proposal the term for imposing an additional tax assessment to private individuals will be 3 years after the date of receipt of the tax return by the tax authorities. If false information was deliberately provided or relevant information was not disclosed to tax authorities, or if the taxpayer knew or should have known he has paid too little tax, the term will be 12 years after the date of receipt of the tax return by the Dutch tax authorities. According to the proposal, a distinction will no longer be made between domestic or non-domestic situations.

The intended starting date for these new rules is January 1, 2014.