30% ruling and old age pension basis as of January 1, 2015

As of January 1, 2015, the tax free allowance of the 30% ruling is taken into account calculating the basis for the old age pension accrual. Prior to January 1, 2015, this was only allowed in certain specific cases e.g. assigned employees who remained  participating into the old age pension plan of their homeland subject to approval by the Dutch tax authorities.