Colt Spam Calls — UK Numbers Most Reported on Our Checker
Ranking of the Colt-allocated UK numbers most-looked-up on our free UK Phone Number Checker. These rankings reflect public lookup interest, which strongly correlates with scam / nuisance call reporting. Currently tracking 1,791 distinct numbers across 3,193 public lookups.
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Top-looked-up Colt numbers
Click any number to see its full lookup page with risk-level, range holder, community reports and related numbers.
| Number | Searches | Last looked up |
|---|---|---|
| 020 3743 6966 | 60 | 3 Jul 2026 |
| 020 4514 7812 | 19 | 2 Jul 2026 |
| 0141 461 4565 | 16 | 3 Jul 2026 |
| 0161 564 5930 | 16 | 29 Jun 2026 |
| 020 4514 9106 | 16 | 21 Jun 2026 |
| 020 4514 7466 | 15 | 29 Jun 2026 |
| 020 4514 7817 | 15 | 25 Jun 2026 |
| 020 3003 2417 | 14 | 19 Jun 2026 |
| 020 4514 7410 | 13 | 30 Jun 2026 |
| 020 4514 8799 | 13 | 19 Jun 2026 |
| 0121 838 0023 | 12 | 24 Jun 2026 |
| 0121 838 0027 | 12 | 3 Jul 2026 |
| 020 3743 6950 | 12 | 2 Jul 2026 |
| 020 3932 2488 | 12 | 1 Jul 2026 |
| 0121 838 0025 | 11 | 23 Jun 2026 |
| 0141 461 4601 | 11 | 3 Jul 2026 |
| 020 3523 0619 | 11 | 2 Jul 2026 |
| 0141 461 4509 | 10 | 23 Jun 2026 |
| 0141 461 4554 | 10 | 17 Jun 2026 |
| 0141 461 4572 | 10 | 30 Jun 2026 |
About Colt in the Ofcom register
Colt is one of the UK communications providers allocated number ranges by Ofcom under the National Telephone Numbering Plan. Number allocations are recorded against the legal entity Colt Technology Services. Numbers within those ranges may now be in active use by the original allocated subscriber, may have been ported to another carrier under UK number portability rules, or may have been re-issued after being returned to the operator's pool — so the Ofcom range holder is not a guarantee of the current call source.
Colt's UK number allocation
Ofcom has allocated 2,007 number blocks to Colt Technology Services. Each block is typically 1,000 or 10,000 consecutive numbers. The mix below shows what kinds of numbers Colt runs — useful context for judging whether a call claiming to be from Colt is plausible.
| Number type | Allocated blocks | Share |
|---|---|---|
| Geographic landline (01 / 02) | 1,676 | 84% |
| UK-wide non-geographic (03) | 110 | 5% |
| Freephone & special-rate (08) | 98 | 5% |
| Premium rate (09) | 88 | 4% |
| Mobile (07) | 24 | 1% |
| Corporate & VoIP (056) | 7 | 0% |
| Service & access codes | 4 | 0% |
Are Colt numbers safe to answer?
Usually, yes — the vast majority of calls from Colt-allocated ranges are ordinary, legitimate calls. But a number sitting in a Colt range is not a guarantee of safety: fraudsters routinely spoof or hijack numbers from every major UK operator, and porting means a number may no longer be on Colt's network at all. Judge each call on what's actually said: never hand over bank details, passwords or one-time security codes to an unexpected caller, and if in doubt hang up and call the organisation back on a number you have verified independently.
How to block and report unwanted Colt calls
Block or report an unwanted number
- You can block an unwanted number directly from your recent-calls list on iPhone or Android, and forward scam texts free to 7726.
- Scam or fraud calls should be reported to Action Fraud (0300 123 2040) or Police Scotland (101); persistent marketing calls to the ICO / TPS.
Full step-by-step instructions for every phone, network-level blocking and all UK reporting routes are in our guide: How to block and report unwanted calls in the UK.
How to stop unwanted calls for good
Blocking Colt numbers stops that one number, but determined nuisance callers simply switch numbers. Silencing unknown callers, enabling your network's free spam shield and registering with the TPS cut the volume across the board — our canonical guide walks through each step: How to block and report unwanted calls in the UK.
Frequently asked questions about Colt numbers
Are Colt numbers always genuine?
No. While Colt is allocated UK number ranges by Ofcom, scammers commonly spoof or hijack numbers from any UK operator's range. A number being in a Colt-allocated block does not guarantee the caller is Colt or Colt-owned.
How do I report a Colt spam call?
Forward spam SMS messages to 7726 (free of charge — works for all UK mobile networks). Report unsolicited marketing calls to the Information Commissioner's Office (ICO) at ico.org.uk/concerns. If you lost money to a scam call, report to Action Fraud at actionfraud.police.uk or 0300 123 2040.
How do I block a Colt number?
On iPhone, tap (i) next to the number in Recents and choose Block this Caller. On Android, long-press the number and choose Block / Report spam. To prevent unknown callers ringing through, enable Settings → Phone → Silence Unknown Callers (iPhone) or your dialler's spam filter (Android).
Why are some Colt numbers reported as scam more than others?
Fraudsters target ranges they know are widely allocated, so the volume of reports per Colt number reflects the size of the active block more than Colt's own conduct. Numbers in newer or larger ranges naturally see more reports purely on volume.
Check another UK number
Or use the free UK Phone Number Checker to look up any UK number — the result shows the Ofcom range holder, risk level, and any community reports on file. You can also add your own report directly on the checker results page.