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Guides › Energy and Water Bills › How Long Does a Company Have to Reply to a Complaint?

How Long Does a Company Have to Reply to a Complaint?

It depends on the sector. Energy suppliers, banks and airlines generally have 8 weeks, phone and broadband providers 6 weeks, and train companies 40 working days. Water companies should reply within 10 working days at each stage. If you get a final response (deadlock letter) sooner, you can usually go to the ombudsman or ADR scheme straight away.

Rules checked with our Energy and Water Bills guide General information, not legal advice
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At a Glance

8 weeksenergy, banks and most financial firms, airlines
6 weeksphone and broadband
40 working daystrain companies
10 working dayswater companies, at each stage

Your Rights

What the rules say, with a link to the official source for each.

Energy and Water

  • The Energy Ombudsman

    If your energy complaint is not resolved within 8 weeks, or you get a deadlock letter, you can take it to the Energy Ombudsman. It is free and impartial. source

  • Tell the Water Company First

    For water, start by telling your water company what is wrong and giving it a chance to fix it. If it does not reply within 10 working days, you may be due a payment under the Guaranteed Standards Scheme. source

  • Ask for a Review

    If you are still unhappy, ask the company to escalate your complaint to a review. It should respond within another 10 working days. source

Phone, Broadband and Trains

  • Free Dispute Resolution

    If your complaint is not resolved, you can use a free alternative dispute resolution (ADR) scheme once six weeks have passed since your initial complaint, or earlier if you receive a deadlock letter. The two schemes are the Communications and Internet Services Adjudication Scheme (CISAS) and the Communications Ombudsman. All providers must belong to one. source

  • The Rail Ombudsman

    If you are unhappy with how the train company handled your complaint, the Rail Ombudsman is free and independent. Allow the company 40 working days to resolve your complaint, or until it sends a final response (a deadlock letter) if that comes sooner. source

Banks and Lenders

  • If You Are Unhappy

    If you are unhappy with how a lender treated you, ask it to put things right first. If you are still unhappy, you can complain to the Financial Ombudsman Service. source

Time Limits to Know

Miss a deadline and you can lose a right. Check the dates on your own paperwork.

  • 8 weeks
    Energy complaint to the Energy OmbudsmanAfter 8 weeks with no resolution, or on receiving a deadlock letter
  • 10 working days
    Water company reply at each of its two stages10 working days
  • 6 weeks
    Wait before going to a free ADR schemeSix weeks from your complaint, or earlier with a deadlock letter
  • 40 working days
    Wait before going to the Rail Ombudsman40 working days from your complaint, or until the company sends a final response (deadlock letter)
  • 8 weeks
    Financial Ombudsman complaintsLender has 8 weeks for most complaints, then you have 6 months from the final response
  • 8 weeks
    Airline should reply to your complaintWithin 8 weeks, then you can escalate to ADR or the CAA

Steps to Take

Step 1 of 5

Complain in writing and note the date. That is when the clock starts.

Step 2 of 5

Ask for a complaint reference. Our free letter templates can write it for you.

Step 3 of 5

Diary the date the business’s time runs out.

Step 4 of 5

If you get a final response (deadlock letter) sooner, you can usually move on straight away.

Step 5 of 5

When the time is up, take it to the ombudsman or ADR scheme for that sector.

(Tap the numbers to reveal steps)

Where to Go If It Is Not Put Right

Your options, in order, and when each one applies.

Energy Ombudsman

After 8 weeks with no resolution, or when you get a deadlock letter.

Consumer Council for Water

After a final response, or 8 weeks after your first complaint.

CISAS or the Communications Ombudsman (ADR)

Six weeks after your complaint, or when you receive a deadlock letter. Free for you. Your provider will say which scheme it belongs to.

Rail Ombudsman

After 40 working days, or once you have a final response (deadlock letter), if the train company is a member of the scheme.

Financial Ombudsman Service

After 8 weeks with no final response, or if you are unhappy with it. Refer within 6 months of the final response.

Good to Know

Small things that make your complaint stronger.

For fraud, scam and payment complaints, banks have a shorter 15-day deadline before you can go to the Financial Ombudsman Service. See your bank’s company guide.

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Luke Marley

Lead reviewer

Luke Marley

Founder and Lead Reviewer

Luke founded CPUK in 2026 after seeing how hard it is for ordinary people to get problems with companies put right. He oversees our guides and checks them against official sources.

Research by Katie Burt, Co-founder and Operations Lead (17 years in the care sector, including managing services for vulnerable adults), and the CPUK Research Team. Researched with AI-assisted research tools, then checked and corrected by our team.

Last checked: 12 October 2026. We are not paid by the companies we write about. Adverts never affect our guidance. Read our editorial policy.

Sources and official links

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