O2 Complaints • 0844 409 8257 • Phone Number

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O2 complaints number:
0844 409 8257
Verified correct on: 12/04/2024

Call costs 5p per minute plus your phone companies access charge.


To complain to O2, call 0844 409 8257. The company have a structured complaints procedure in compliance with regulatory body Ofcom, and details of this are outlined on the website.

O2 is the trading name of Telefonica Europe plc, a European telecommunications and broadband company.



O2 has its origins back in the very earliest days of mobile telephony in the mid-1980’s under the stewardship of BT (then British Telecom) when the brand was known as Cellnet (later BT Cellnet when it became part of BT Wireless, a group of subsidiaries owned by BT).

In late 2001, BT Cellnet demerged from BT and was relaunched in May 2002 as O2. This brand name (the chemical symbol for unbound oxygen) was chosen since, like oxygen, what the company provides could be considered essential.

In 2005, Telefonica took O2 over although they stayed in the UK and retained their basic management structure and branding.

With over 23 million customers, O2 runs 2, 3 and 4G networks across the country and owns half of Tesco Mobile. There are some 450 O2 retail stores, and the company has a good satisfaction record according to the most recent statistics from Ofcom (see below).

Making a complaint

Speak to O2 on 0844 409 8257 (Mon - Fri 8.00am - 9.00pm, Sat 8.00am - 8.00pm, Sun 8.00am - 6.00pm) to try and resolve your complaint, or set in motion the official complaints procedure if necessary. The website has details of how to complain and other contact options under ‘customer support’ in the ‘how to complain’ section.

As well as by telephone, contact can be made by post or live chat. O2 have a ‘complaint review service’ that can look at your complaint if initial contact with the company has been fruitless (they can also be emailed via the website).

Failing these measures, you can then contact the independent Ombudsman (details below). Before doing so, you should ensure you have followed O2’s complaints procedure IN FULL and be in possession of a ‘deadlock letter’ from the company which is their final offer of a resolution to your complaint.

O2 came first in the most recent (2013) Ofcom mobile phone provider customer satisfaction survey (they were also first in 2012).

Useful information

Website: www.o2.co.uk

Complaints No: 0844 409 8257

Postal address:
Telefonica UK Ltd
Correspondence Department
Houghton Regis
PO Box 202

Ombudsman Services
PO Box 730

Web: www.ombudsman-services.org

O2 complaints number:
0844 409 8257
Verified -

Calls cost 5p per minute plus your phone companies access charge.

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