Verified: 9 March 2026 08:35 pm UK Time
Industry: Mobile Telecommunications (MVNO) & Consumer Credit
Jurisdiction: United Kingdom
Primary Regulators: Ofcom & Financial Conduct Authority (FCA)
Important Safety Warning: Beware of fake customer service numbers on search engines. Only use official channels. Scammers frequently buy ads to promote fraudulent phone numbers. Tesco Mobile staff will never ask for your account PIN, your online portal password, or ask you to read back a one-time security code to verify your identity over the phone.
Level 1: Customer Support (Initial Complaint)
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How to complain: You can raise a complaint directly through your Tesco Mobile app, via web chat, or by calling their official customer service routing numbers.
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Tesco Mobile Customers: Dial 4455 from your Tesco mobile (Free)
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From any other phone: 0345 301 4455 (Standard UK rates apply)
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Business Customers: 0345 601 2448
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Source Verification Note: Tesco Mobile Complaints Code of Practice
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Availability: Telephone support is available Monday to Friday from 8:00 AM to 9:00 PM, Saturday from 8:00 AM to 8:00 PM, and Sunday/Bank Holidays from 10:00 AM to 6:00 PM (UK Time).
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Timeline: Tesco Mobile aims to resolve complaints on the first call. If they cannot, their Complaints Management team aims to share an outcome within 7 working days.
Level 2: Formal Corporate Escalation (Notice of Dispute)
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Who to contact: If standard customer service cannot resolve the issue, you must formally escalate it to their central correspondence team. Send a written letter detailing your account number, a timeline of the issue, and your desired resolution. You must explicitly request a “Deadlock Letter” if they refuse your proposed resolution. Sending this via Royal Mail Signed For is highly recommended to prove receipt.
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Complaints Address: Tesco Mobile, PO Box 710, Darlington, DL1 9JU
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Timeline: Under UK regulations, Tesco Mobile has a maximum of 8 weeks to issue a final resolution or a Deadlock Letter.
Level 3: Regulatory Authority (Government Ombudsman)
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Authority: Communications Ombudsman OR Financial Ombudsman Service (FOS) * Portal/Contact: You must route your complaint to the correct ombudsman based on the nature of the dispute:
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Network/Service/Airtime Complaints: Escalate to the Communications Ombudsman. (Phone: 0330 440 1614)
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Handset Financing/Credit Agreement Complaints: Escalate to the Financial Ombudsman Service. (Phone: 0800 023 4567)
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Timeline (CRITICAL): You can only refer your complaint to an Ombudsman after you receive a Deadlock Letter from Tesco Mobile, OR if 8 weeks have passed since your initial complaint without a resolution.
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Service Complaints: You have 12 months from the Deadlock Letter date to escalate to the Communications Ombudsman.
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Financial Complaints: You have a strict 6 months from the Deadlock Letter date to escalate to the FOS.
Level 4: Legal Action (Final Step)
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Pre-Litigation: Before commencing legal proceedings, UK legal protocols require you to send a formal “Letter Before Action” (LBA) to Tesco Mobile’s corporate legal headquarters. This letter must outline your claim, the exact legal or contractual breach, the evidence, and the financial remedy you seek, giving them a final 14 to 30 days to settle.
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Legal Address: Tesco Mobile Limited, Tesco House, Shire Park, Kestrel Way, Welwyn Garden City, AL7 1GA
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Court: If the LBA fails and the Ombudsman cannot resolve it, you can file a lawsuit. For financial claims up to £10,000 in England and Wales, you can use the Money Claim Online (MCOL) portal to enter the Small Claims Track. For complex claims, you will likely need to instruct a solicitor and proceed to the County Court.
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Source Verification: Make a court claim for money (GOV.UK)
Community Action: Is Tesco Mobile still ignoring your signal dropout issue or financing dispute? Reply below (do not share your passwords, full account numbers, or PINs), and our community will point you to the right Ombudsman complaint templates!