On 14 May 2018, Germany's Federal Fiscal Court issued a decision suspending the additional interest penalty of 0.5% per month on unpaid taxes, finding the additional interest to be unconstitutional. The 0.5% simple interest penalty applies for each full month beginning 15 months after the expiration of the calendar year for which the tax is assessed. The interest is in addition to other late tax payment penalties, and also applies in relation to tax refunds. The 0.5% rate has not been change…