The first day of June this year saw the entry into force of amendments to the Act on Rules for Registering and Identifying Taxpayers and Tax Remitters, of 13 October 1995 (Act). They have redefined the rules concerning the PESEL (Universal Electronic System for Registration of the Population) and NIP (Taxpayer Identification Number) tax identifiers. As a result, PESEL has become the primary identifier for taxpayers who are individuals and are not registered as taxpayers of goods and services or are not engaged in business. According to the justification for the Act, the amendments are intended to enable foreigners to obtain a PESEL identifier without having to register their stay and does away with the practice of assigning NIP numbers to such persons. This change is of great practical significance, particularly for persons providing HR and payroll services to companies employing foreigners.