What changed
Spain has reserved the '400' number range (nine-digit numbers starting with 400) exclusively for commercial calls, implementing the 2025 Customer Service Act. Numbers in this range can only be used for outbound commercial calls and cannot receive return calls, preventing fraud and confusion for consumers.
Who is affected
Businesses that make commercial (sales and marketing) phone calls must use 400-range numbers for those calls. For consumers, incoming calls from 400 numbers are a clear signal they are commercial in nature; there is no point calling back as the number cannot receive calls.
What to look out for
→ No action required from consumers. Businesses making commercial calls must migrate to 400-range numbers according to timelines set by implementing regulations.
⚠️ This explanation was created with AI assistance and may be inaccurate or incomplete. It is not legal advice. Before taking action, check the official text and consult a qualified lawyer.
Original law: BOE-A-2026-8409 — Check the official text before relying on this explanation.