Ofcom spent six months investigating the company
Independent retailer Phones4U broke the law over mis-selling mobile phone contracts, a six-month investigation by the telecoms regulator Ofcom found.
The retailer misled customers over network coverage, failed to swiftly provide refunds for faulty handsets and had unfair terms on chequeback schemes.
Phones4U was the first retailer in the UK to face an inquiry by Ofcom despite mis-selling being a common complaint.
The investigation prompted it to change policies and sales practices.
"Phones 4U has given Ofcom a series of undertakings to ensure that similar issues do not rise again. We feel that this matter has now been fully resolved," it said in a statement.
It has 440 outlets in the UK.
The regulator launched the inquiry, together with trading standards officers, after it received "a large number" of complaints about alleged mis-selling and other issues by the independent retailer.
In March, Ofcom said it would crack down on the mis-selling of mobile phones after the failure of a voluntary code of practice across the industry.