Article 4a: legal basis for bias testing with special categories of personal data

Paragraph 2 provides that providers and deployers of other AI systems and models and deployers of high-risk AI systems may exceptionally process special categories of personal data to the extent that: (a) such processing is strictly necessary to ensure bias detection and correction in view of possible biases that are likely to affect the health and safety of persons, have a negative impact on fundamental rights or lead to discrimination prohibited pursuant to Union law, especially where data outputs influence inputs for future operations; and (b) all of the conditions and safeguards set out in paragraph 1 are applied. Paragraph 2 closes with a separate subparagraph: this paragraph does not create any obligation to conduct such bias detection and correction. Article 4a has no paragraph 3.

Regulation (EU) 2026/1744 inserts Article 4a into Regulation (EU) 2024/1689 by Article 1, point 6, and deletes Article 10(5) by Article 1, point 9(b). The same point 9 replaces Article 10(1) and Article 10(6) so that they now refer to the quality criteria in Article 4a(1). The basis therefore no longer sits with the requirements for high-risk systems in Chapter III, but as a standalone article in Chapter I, immediately after Article 4, while Article 10 refers back to it from the outside. In the Dutch language version of the Official Journal the inserted article is numbered "artikel 4 bis"; "Article 4a" is the English numbering of the same provision.

The same amending Regulation replaces Article 2(7) of Regulation (EU) 2024/1689 by Article 1, point 2(b). Since 27 July 2026 that paragraph reads: "Union law on the protection of personal data, privacy and the confidentiality of communications applies to personal data processed in connection with the rights and obligations laid down in this Regulation. Without prejudice to Articles 4a and 59 of this Regulation, this Regulation shall not affect Regulation (EU) 2016/679 or (EU) 2018/1725, or Directive 2002/58/EC or (EU) 2016/680." The previous version of that paragraph carried no such reservation for Article 4a.

Recital 9 of Regulation (EU) 2026/1744 states that bias detection and correction constitute a substantial public interest, that the extended legal basis is subject to the same limitations, conditions and safeguards as the existing Article 10(5), and that this thereby ensures compliance with Article 9(2), point (g), of Regulation (EU) 2016/679, Article 10(2), point (g), of Regulation (EU) 2018/1725 and Article 10, point (a), of Directive (EU) 2016/680. The same recital states that the legal basis established by Article 4a should apply from the date of entry into application of Regulation (EU) 2024/1689, so as to enable providers of high-risk AI systems lawfully to undertake bias detection and correction activities in preparation for compliance with the requirements for high-risk AI systems. Article 4 of the amending Regulation governs only entry into force on the third day following publication and provides for no deferred application; the amended Article 113, third paragraph, point (a), provides that Chapters I and II apply from 2 February 2025, with the exception of Article 5(1), first subparagraph, points (ba) and (bb), and Article 5(1a) and (1b), which apply from 2 December 2026. Article 4a sits in Chapter I and falls outside that exception.

Three things matter more in practice than the relocation itself. The first is that this article instructs you to do nothing. Paragraph 2 says so in as many words, and no date by which anything must be done belongs with it either. The second, and the more dangerous misreading, is that the move into Chapter I means you may now start collecting sensitive attributes because you want to run fairness measurements. What has widened is the set of parties, not the room inside the basis: recital 9 expressly states that the same limitations, conditions and safeguards apply as under the former Article 10(5). In practice it therefore starts with a written justification of why synthetic or anonymised data do not suffice, and not with assembling a dataset. The third is the condition that bites hardest and appears in no summary: point (d) provides that the data are not transmitted, transferred or otherwise accessed by other parties. That is in effect a ban on outsourcing. An external fairness vendor, a bias auditing firm, a research partner or a cloud party that can reach the data itself does not fit inside this basis, however good the contract. Anyone who intended to buy in their bias testing must run it in house here, or work with data that are not a special category. Finally, watch your own documentation: records of processing, data protection impact assessments and AI policy documents that refer to Article 10(5) have been referring to a deleted provision since 27 July 2026. The same holds for documents citing Article 2(7) to argue that the GDPR prevails without qualification: that paragraph too has been replaced and now expressly reserves Articles 4a and 59. Two dates to close on, and the second is our inference rather than source text. Article 4a sits in Chapter I, which under Article 113, third paragraph, point (a), has applied since 2 February 2025, but the provision only entered the text on 27 July 2026; we therefore treat 27 July 2026 as the day the basis actually became available, while recital 9 states that it should apply from the date of entry into application of Regulation (EU) 2024/1689. Finally, note that the requirements in Article 10(2), points (f) and (g), which paragraph 1 refers to, themselves only start to apply on 2 December 2027 for Annex III systems and on 2 August 2028 for Annex I systems. The basis therefore deliberately runs ahead of the duty you use it for, exactly as recital 9 intends.