# Article 4 — Acknowledgment of receipt of a complaint and verification of its admissibility **Commission Delegated Regulation (EU) 2025/294 · binding · OJ L, 2025/294, 13.2.2025 · dated 1 Oct 2024 [in force]** *In force · Commission Delegated Regulation (EU) 2025/294, OJ L, 2025/294, 13.2.2025 · Checked against EUR-Lex on 26 Oct 2026 · [Official source](https://eur-lex.europa.eu/eli/reg_del/2025/294/oj/eng)* 1. Crypto-asset service providers shall acknowledge receipt of a complaint and inform the complainant about whether the complaint is admissible without undue delay after having received the complaint. 2. Where a complaint does not fulfil the conditions of admissibility referred to in Article 1(2), point (a), crypto-asset service providers shall provide the complainant with a clear explanation of the reasons for rejecting the complaint as inadmissible. 3. The acknowledgment of receipt of a complaint shall contain all of the following:\ a) The name, identity and contact details, including email address and telephone number, of the person to whom, or the department to which, complainants can address any query related to their complaint;\ b) the date of receipt of the complaint;\ c) a reference to the timeframe referred to in Article 1(2), point (e);\ d) where an electronic complaint form is filed, a copy of the complaint.