Sources & references
Every primary source WhoCalledLookup cites across its lookup tools, cornerstone guides and result pages. This is the single authoritative bibliography for the site — the same source registry every guide pulls from, presented as a single page so readers and AI engines can audit provenance without walking the entire blog.
38 sources listed. Last reviewed: . See the methodology for how each source is used.
Ofcom
The UK telecoms regulator. The Numbering Data feed is the source of every range-holder result on the site; the Numbering Plan and the various CLI and call-charge documents are the regulatory backdrop for the cornerstone guides.
- National Telephone Numbering PlanOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/numbering-policy/numbering-plan
- UK Numbering Data (weekly feed)Ofcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/numbering-data
- UK Calling: clearer call chargesOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/clearer-call-charges
- Service-charge rules for 084, 087, 09 and 118 numbersOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/clearer-call-charges/service-charges
- Tackling scam calls: CLI authenticationOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/scam-calls-and-texts/cli-authentication
- Calling Line Identification (CLI) rulesOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/scam-calls-and-texts/cli-authentication
- Complaining to Ofcom about silent and nuisance callsOfcom · Last verifiedhttps://www.ofcom.org.uk/complaints
- Personal numbers (070): consumer guidanceOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/personal-numbers
- Calling 0800 and 0808 numbers from mobiles is free (since July 2015)Ofcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/clearer-call-charges/freephone
- UK number portability rulesOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/switching/switching-broadband-or-phone
- Tackling scam calls and texts: 2024 progress reportOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/scam-calls-and-texts
- UK mobile-number allocations — 07 ranges by MNOOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/numbering-policy/numbering-plan
- Non-geographic 03 numbers — guidance for public bodiesOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/clearer-call-charges
- 056 location-independent VoIP numberingOfcom · Last verifiedhttps://www.ofcom.org.uk/phones-and-broadband/phone-numbers/numbering-policy
Government & regulators
Statutory bodies whose published guidance underpins the safety and reporting routes on the site.
- Report a phishing or scam callgov.uk · Last verifiedhttps://www.gov.uk/report-suspicious-emails-websites-phishing
- HMRC: examples of genuine and scam contactHMRC / gov.uk · Last verifiedhttps://www.gov.uk/government/publications/genuine-hmrc-contact-and-recognising-phishing-emails
- Privacy and Electronic Communications Regulations (PECR)Information Commissioner's Office · Last verifiedhttps://ico.org.uk/for-organisations/direct-marketing-and-privacy-and-electronic-communications/guide-to-pecr/
- Data Protection Act 2018 + UK GDPR overviewInformation Commissioner's Office · Last verifiedhttps://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/
- Action Fraud — UK fraud reportingCity of London Police · Last verifiedhttps://www.actionfraud.police.uk
- Forwarding suspicious texts to 7726National Cyber Security Centre · Last verifiedhttps://www.ncsc.gov.uk/collection/phishing-scams/report-scam-call
- 159 — the Stop Scams UK serviceStop Scams UK · Last verifiedhttps://stopscamsuk.org.uk/159
- Telephone Preference Service (TPS)DMA / TPS · Last verifiedhttps://www.tpsonline.org.uk
Industry standards & developer references
The international standards and open-source libraries that define UK phone-number format, validation and line-type intelligence.
- ITU-T Recommendation E.164: international public telecommunication numbering planITU · Last verifiedhttps://www.itu.int/rec/T-REC-E.164
- libphonenumber — Google's phone-number libraryGoogle · Last verifiedhttps://github.com/google/libphonenumber
- libphonenumber-js — JavaScript port@catamphetamine · Last verifiedhttps://github.com/catamphetamine/libphonenumber-js
- Twilio Lookup API — Line Type IntelligenceTwilio · Last verifiedhttps://www.twilio.com/en-us/lookup
- Vonage Number Insight APIVonage · Last verifiedhttps://developer.vonage.com/en/number-insight/overview
- Phone-paid Services Authority — Code of PracticePhone-paid Services Authority · Last verifiedhttps://psauthority.org.uk/for-business/code-of-practice
UK public services
Statutory consumer services we cite when recommending the right number to ring for a given situation.
- NHS 111 — when to use itNHS · Last verifiedhttps://www.nhs.uk/nhs-services/urgent-and-emergency-care-services/when-to-use-111
- Police 101 non-emergency numberPolice.uk · Last verifiedhttps://www.police.uk/contact-us/non-emergency
- 105 — UK power-cut helplineEnergy Networks Association · Last verifiedhttps://www.powercut105.com
- Royal Mail — How to spot a scamRoyal Mail · Last verifiedhttps://www.royalmail.com/help/scam-protection
- BT 1471 / 1572 / Anonymous Call RejectionBT · Last verifiedhttps://www.bt.com/help/landline/calling-features-and-security/anonymous-call-rejection
- UK Finance — Take Five to Stop FraudUK Finance · Last verifiedhttps://www.takefive-stopfraud.org.uk
Consumer community sources
Public community boards and consumer-protection resources the AI internet check searches when summarising what the public web says about a specific number.
- who-called-me.com — UK community phone-number reportswho-called-me.com · Last verifiedhttps://who-called-me.com
- whocallsme.com — international community reportswhocallsme.com · Last verifiedhttps://whocallsme.com
- Say No To 0870 — free alternatives to 084/087 numbersSayNoTo0870.com · Last verifiedhttps://www.saynoto0870.com
- Helplines Partnership — UK helpline directoryHelplines Partnership · Last verifiedhttps://helplinespartnership.org.uk