According to this rule, in case of doubts related to the interpretation of the given legal provision, these shall be decided in favour of an entrepreneur applying the provision. From any taxpayer's (including foreign investors') standpoint, the newly amended rule is of great importance. It means that if, while properly following the rules of legal provisions interpretation, more than one outcome shall be found, the tax authorities cannot challenge the solution chosen by a taxpayer in line with any of the abovementioned outcomes of the interpretation. This rule will be complied with by the tax authorities (while auditing taxpayer settlements) as well as by the tax courts.
Although, up to the end of December 2015, the abovementioned rule could be interpreted based on the Polish constitution, the tax authorities were commonly disregarding it by issuing decisions favourable for the budget, against the rule itself though.
It should, however, be stressed out that the 'in dubio pro tributario' rule will apply only to the removal of doubts related to interpretation of the law – and will not be applicable in the case of a dispute between the taxpayer and the tax authorities regarding the circumstances of the case. Should this be the case, the general rules of assessment of the evidence shall be applied.