Deadlock Letter

A deadlock letter (also called a final response letter) is issued when a company has concluded its internal complaints process without resolving the matter to your satisfaction. In regulated sectors such as energy, financial services, and communications, firms must issue a final response within 8 weeks of receiving a complaint, and the letter must tell you which ombudsman or ADR scheme you can go to next. If no final response arrives within 8 weeks, you can treat the complaint as deadlocked and refer it anyway.

What it means in practice. The letter is a key that unlocks the free external route. It matters far less what it says than that it exists and is dated. A letter that says "our position remains unchanged" or "we consider this matter closed" performs the same function as one headed "final response". Read it for two things: the date, because that starts the referral clock, and the named scheme, because referring to the wrong body wastes weeks.

A worked example. Tom disputes £340 of charges on a broadband account. He complains on 3 March. The provider offers £40 and, on 12 April, sends a letter setting out its final position and naming its approved ADR scheme. Tom now has a deadlock letter dated 12 April. He refers the dispute to the scheme within the window given in the letter, attaching his original complaint, the billing evidence, and the final response. The scheme reviews the file and orders a larger refund.

Common pitfalls. The first is waiting for a letter that never comes: many firms simply go quiet, and people wait months rather than exercising the right to refer once 8 weeks have passed. The second is not recognising a final response when it arrives, because it is buried in a routine-looking email — the clock still runs. The third is missing the referral deadline, which for the Financial Ombudsman Service is normally six months from the final response. Once that window closes, the free route usually closes with it.

How it relates to other terms. A deadlock letter and a final response letter are the same document described two ways — "deadlock" is the term used in energy and communications, "final response" is the FCA term. It is the gateway to an ombudsman or an approved ADR scheme, and the 8-week deadline that produces it is set by the sector regulator — the FCA for financial firms, Ofgem for energy, Ofcom for telecoms.

What to do next. Read our guide to deadlock letters to see how to request one in writing, and use complaint timelines to diary the 8-week and referral deadlines the day you complain. When the letter arrives, move straight to escalating your complaint.