How to Report Nuisance Callers to Three

The Challenge of Reporting Hidden Callers on Three

Reporting severe harassment, persistent telemarketing, or scam calls to the Three UK Network is critical for stopping illegal activity. However, there is a major roadblock: you cannot effectively report a "No Caller ID" call because there is no actionable data to investigate.

Step 1: Gather the Evidence (Unmasking)

Before making a report to Three, you need the perpetrator's actual phone number. By using a call intelligence tool like MaskOff UK, you can intercept the hidden call and strip away the anonymity block.

• Decline the anonymous call to route it to our secure system.
• Instantly receive the real UK or international phone number.
• Log the exact date, time, and duration of the call (available in your dashboard).

Step 2: Where to File Your Report

Now that you have the evidence, text the unmasked number to 7726 or provide it directly to Three customer service. Armed with the actual number, the network can ban the SIM card and investigate the abuser.

Taking Back Control

By unmasking hidden numbers, you stop being a passive victim and gain the tools necessary to block them locally and hold them legally accountable.

Related UK Safety & Evidence Guides: Read our step-by-step guide on preparing 101 police-ready phone harassment evidence, review the 2026 UK study on chronic phone harassment, or learn how conditional call forwarding unmasks 141 calls.