Think You are Being Overcharged on Your Business Mobile Bill? Here is How to Check.

Last updated: March 2026

You probably are.

That is not a guess. According to research by the Federation of Small Businesses, around 63% of UK SMEs are paying more than they need to on their business mobile contracts. Not a little more. An average of 28% more. For a company with 10 mobile lines, that is roughly £1,200 to £3,600 per year, going straight into your network's pocket instead of yours.

The worst part? You do not even know it is happening. Nobody sits down and reads their mobile bill line by line. It arrives as a PDF. It is confusing. There are charges for things you have never heard of. The numbers are small enough individually that nothing jumps out. But collectively? They add up to thousands.

At Compare The Networks, we have audited over 12,000 business mobile bills since 2008. And in the vast majority, over 80%, we find savings. Not by switching to a worse deal. Not by cutting features your team needs. Just by identifying charges that should not be there, plans that do not match usage, and contracts that should have been renegotiated months ago.

This guide will show you exactly how to check if you are being overcharged. You can do it yourself in about 30 minutes. Or you can send us your bill and we will do it for free within 24 hours. Either way, you will know.

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The 7 Most Common Business Mobile Overcharges

These are the charges we find on bill after bill, month after month. Most businesses have at least two of these. Many have five or more.

1. Paying for Data You Never Use

This is the most common overcharge we see, and it is costing UK businesses millions every year.

Here is how it happens: when you set up your business mobile contract, you estimated how much data each employee would need. You probably overestimated, because nobody wants to be the person who runs out of data. So you went for the 20GB plan instead of the 10GB plan. "Better safe than sorry."

But here's the thing. According to OFCOM's 2025 Communications Market Report, the average UK business mobile user consumes 6.8GB of data per month. That means if you are on a 20GB plan, you are wasting 13GB every single month. At roughly £1.50-£2.00 per GB in plan pricing, that is £20-£26 per month per line being thrown away.

The maths on a 15-person team:

And that is just data. Some of your team will be using even less. The accounts person who barely leaves the office and is on WiFi all day? They are probably using 2GB. The receptionist? Maybe 1GB. You are paying for 20GB each.

How to check: Log into your network's business portal. Look at data usage for each line over the last 3 months. If anyone is consistently using less than 50% of their allowance, they are on the wrong plan.

2. Out-of-Contract Price Increases

This is the one that makes people genuinely angry when they discover it.

When your contract ends. Whether it is a 24-month or 36-month deal, you do not automatically get the best available rate. Instead, most networks move you to a "standard" or "out-of-contract" rate. This is almost always more expensive than what new customers are paying.

How much more? Between 15% and 40% more. We have seen businesses paying £35/month for a plan that new customers can get for £22/month. Same network. Same data. Same minutes. Different price.

On top of that, every major UK network now applies annual mid-contract price rises linked to CPI or RPI inflation, typically 3-7% per year. So a plan that cost £25/month when you signed up could be costing £28-£30/month two years later, before you even go out of contract.

The kicker: Networks are not required to tell you when you go out of contract. They will happily keep charging you the higher rate until you notice. Some businesses have been out of contract for years without realising it.

How to check: Call your network (or better yet, call us) and ask for the contract end date on every line. If any line is out of contract, you are almost certainly overpaying. Compare your current rate to the best deal currently available for the same usage level.

3. Insurance on Old Phones

You bought your team new iPhones three years ago. You added insurance at £12/month per phone. Sensible decision at the time, since a new iPhone costs £800+.

Three years later, those phones are worth maybe £50-£100 on the second-hand market. But you are still paying £12/month insurance on each one. That insurance is costing you £144/year per phone to protect a device worth a fraction of that.

For a team of 10, that is £1,440/year in insurance premiums on phones that are essentially worthless. If one breaks, you'd be better off just buying a replacement outright.

How to check: Look at your bill for any charges labelled "insurance," "device care," "phone protection," or similar. Then check what the insured device is actually worth on a site like musicMagpie or CeX. If the annual insurance cost exceeds the phone's value, cancel it immediately.

4. Unused Lines (Ghost Lines)

This one is embarrassingly common, and nobody wants to admit it.

An employee leaves. Their phone gets put in a drawer. Nobody remembers to cancel the line. The direct debit keeps going out. Months pass. Sometimes years.

We recently audited a 30-person company and found 7 active lines belonging to ex-employees. Seven. At an average of £28/month each, that is £196/month, or £2,352/year, on phone lines that nobody is using. One line had been active and billing for over three years after the employee left.

How to check: Get a list of every active mobile line on your account. Match each one to a current employee. If you cannot match a line to a person, it should not be there.

5. Roaming Charges Nobody Knew About

Business roaming is a minefield. Some plans include EU roaming. Some do not. Some include data roaming but cap it at 12GB. Some charge £2/MB for data outside the EU. One employee's week-long trip to Dubai can generate a £500 bill if they do not switch to WiFi.

Since Brexit, EU roaming "guarantees" have changed. Most networks now impose fair usage limits or charge extra for EU roaming. If your team travels regularly and your plan does not include roaming, you could be paying hundreds per month without realising it.

How to check: Search your bill for charges from any country other than the UK. Look for terms like "roaming," "international," or specific country names. Then check your plan terms. Is roaming included? Is there a fair usage cap? What happens when you exceed it?

6. Premium Rate Numbers

These are sneaky. An employee calls a technical support number that turns out to be a premium rate line. Or they call a competition entry line. Or they get connected to a service via a 09 number without realising it costs £3.50/minute.

Premium rate charges appear on your mobile bill and are often missed because they are just one line item among many. But a single 20-minute call to a premium rate number can cost £70.

How to check: Search your itemised bill for any calls to numbers starting with 09, 118, or 087. These are almost always premium rate. If you find them, consider adding a premium rate bar to your lines. All networks offer this for free.

7. "Free" Extras That Aren't Free After the Trial

Networks love bundling "free" extras with business contracts. BT Sport for 3 months. Cloud storage for 6 months. A security app for 90 days. The trial period ends. The charge starts. Nobody notices because it is only £5-£8/month per line.

But £5/month across 15 lines is £75/month. £900/year. For a service that nobody asked for and nobody is using.

How to check: Look for any recurring charges on your bill that are not your core plan cost, data, or calls. Anything described as a "subscription," "add-on," "extra," or "bolt-on" should be scrutinised. If nobody in your team is actively using it, cancel it.

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How to Audit Your Business Mobile Bill (30-Minute Guide)

You can do this right now. All you need is your last three bills, a spreadsheet, and 30 minutes.

Step 1: Get Your Last 3 Bills

Download them from your network's business portal. If you cannot access the portal, request them by calling or emailing your provider. You want PDF copies with full itemisation, not just the summary page.

Why 3 months? Because one month might be an anomaly. Three months shows you the pattern.

Step 2: List Every Line and Its Monthly Cost

Create a spreadsheet with these columns:

If you cannot match a phone number to a current employee, highlight it in red. That is probably a ghost line.

Step 3: Check Data Usage vs Allowance for Each Line

For each line, note the data allowance and the actual usage over the last 3 months. You are looking for lines where usage is consistently below 50% of the allowance.

Sarah is using 22% of her data allowance. She is massively over-provisioned. Dave is using 40% of his, still overpaying, but closer to right.

Step 4: Check for Out-of-Contract Lines

For each line, note when the contract started and its length. Calculate the end date. If it is in the past, that line is out of contract and you are almost certainly paying more than you need to.

Step 5: Check for Insurance on Old Devices

For every line with insurance, note the insured device and its approximate current value. If the annual insurance cost exceeds the device value, flag it.

Step 6: Look for Charges You Do not Recognise

Go through the itemised section of each bill. Look for:

• Premium rate calls (09, 118, 087 numbers)
• International calls you did not authorise
• Subscription services or bolt-ons
• Roaming charges
• "One-off" charges that appear every month
• MMS charges (nobody sends MMS anymore. If there are charges, something is wrong)

Step 7: Total It Up and Compare

Add up everything you are spending. Then calculate what you should be spending based on actual usage patterns.

The gap between these two numbers is what you are overpaying.

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Worked Example: How a 12-Person Business Saved £287/Month

Here is a real audit we conducted for a recruitment agency in Leeds. 12 mobile lines with a major UK network. They thought their mobile bill was "about right." It was not.

Before the Audit

What We Did

1. Cancelled the 2 ghost lines immediately. No early termination fee because both were out of contract.
2. Moved 7 lines from 20GB to 10GB plans at the next available date. No downgrade fee, as they had more than enough data.
3. Cancelled insurance on 5 old devices. Phones were worth less than the annual premium.
4. Renegotiated the 3 out-of-contract lines to current pricing. This alone saved £14/line/month.
5. Cancelled BT Sport and roaming bolt-ons on all affected lines.
6. Set up alerts so the business is notified when any contract is approaching its end date.

After the Audit

Monthly bill went from £1,124 to £837. Annual saving: £3,444. And the team had exactly the same service. Same data, same calls, same coverage. They were just no longer paying for things they did not need.

Total time the customer spent on this: one phone call with us lasting 20 minutes, during which they authorised us to act on their behalf. We handled everything else.

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How to Negotiate With Your Current Provider

If you have done the audit and found overcharges, you have two choices: fix it yourself or let us do it. If you want to try yourself, here's how.

What to Say

Call your network's business line (see our direct numbers guide if you cannot get through) and use these phrases:

• "I have audited my bill and found that I am paying for services I do not use. I would like to remove them." This is factual and hard to argue with.
• "I am out of contract on X lines. What is the best rate you can offer me for renewal?" Forces them to quote you. Their first offer will not be their best.
• "I have received competitive quotes from other networks for the same service at a lower price." This is the leverage that matters. If you have not actually got other quotes, get them first. Or call us and we will get them for you.

When to Threaten to Leave

Only threaten to leave if you are actually willing to follow through. Networks can tell when you are bluffing. If you say "I will leave" and then do not, you have used your only leverage.

The most effective approach is:

1. Get genuine quotes from competing networks (or from us, as we quote all four).
2. Call your current network and ask for their best retention offer.
3. Compare the retention offer to the competing quotes.
4. If the retention offer is competitive, take it. If not, leave.

Do not be afraid to actually leave. Switching business mobile provider is much easier than networks want you to believe. PAC codes are legally required within one working day. Number porting takes 1-3 working days. The whole process can be done in under a week.

Escalation Paths

If the front-line agent cannot help:

1. Ask for a manager. The first agent has limited authority. A team leader can usually approve credits and plan changes that the front-line agent cannot.
2. Ask for the retentions team. This is the team with the best deals and the most authority. But they will only speak to you if you have indicated you are considering leaving.
3. File a formal complaint. This creates a paper trail and triggers an internal review process with a dedicated complaint handler.
4. Email the executive office. See our direct contact details guide for CEO email addresses.
5. Escalate to OFCOM ADR. If 8 weeks have passed without resolution, or you have received a deadlock letter.

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When It is Cheaper to Switch Than Negotiate

Sometimes your current network simply cannot or will not match what is available elsewhere. Here are the signs:

• Their best retention offer is still 15%+ more expensive than competing quotes. They are not serious about keeping you.
• You are on an old tariff structure that no longer exists. Some legacy plans cannot be modified. You would need a new contract anyway.
• Your contract end dates are staggered across 12+ months. It may be cheaper to pay early termination on a few lines and consolidate everything onto a better deal.
• Coverage has deteriorated since you signed up. If the network has decommissioned masts or your area has not received promised upgrades, you may have grounds to exit without penalty.
• Your business needs have fundamentally changed. You have grown from 5 to 25 people, or you have moved office, or your team now works remotely. The plan you signed up for does not fit anymore.

In these cases, the cost of staying usually exceeds the cost of switching, even accounting for any early termination fees.

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How Compare The Networks Does a Free Bill Audit

Here is what happens when you send us your bill:

1. You send us your latest bill. Email it to us, upload it via our website, or we will walk you through how to download it during a call. We need the full bill with itemisation, not just the summary page.

2. We analyse every line. Data usage vs allowance. Contract status. Insurance. Bolt-ons. Roaming. Premium rate charges. Everything listed in this guide, plus a dozen things you would not know to look for.

3. We compare your current deal to the market. We check pricing from EE, Vodafone, O2, and Three for your exact requirements: same number of lines, same data needs, same coverage area. We know prices that are not publicly advertised because we are a registered partner with all four networks.

4. We present our findings. Within 24 hours, you will get a clear summary: what you are paying now, what you should be paying, and how to get there. No jargon. No sales pressure. Just the numbers.

5. You decide what to do. If you want to fix things yourself, we have given you the roadmap. If you want us to handle it, the negotiation, the switching, the PAC codes, the whole lot, we do it at no cost to you.

We have done this over 12,000 times since 2008. We are OFCOM-regulated and rated 4.3/5 on Trustpilot. We do not work for the networks. We work for you.

If your audit shows you are overpaying, get a free quote and we will show you what the right deal looks like.

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Frequently Asked Questions

How do I know if I am being overcharged?

If you have not reviewed your business mobile bill in the last 6 months, there is a very high chance you are overpaying somewhere. The most common signs are: lines you cannot match to current employees, data allowances much higher than actual usage, insurance on old phones, and paying more than what is currently advertised for similar plans.

Will switching network save me money even with early termination fees?

Often, yes. Early termination fees are typically the remaining monthly charges on your contract. If you are overpaying by 30% and have 12 months left, the savings from switching to a correctly-priced plan can exceed the termination fee within 6-9 months. We calculate this for you as part of our free audit.

Can I reduce my plan mid-contract?

It depends on the network and your contract terms. Most networks allow you to downgrade data mid-contract, though some lock you in at the originally agreed level. Bolt-ons, insurance, and extras can usually be removed at any time. We can advise on what is possible with your specific contract.

My bill is confusing. I cannot understand the charges. Is that normal?

Unfortunately, yes. Mobile bills are notoriously confusing, especially for business accounts with multiple lines. This is partly by design. If you cannot understand the bill, you cannot challenge it. Our free bill audit translates your bill into plain English and highlights exactly what you are paying for.

How much does an average business save after a bill audit?

Across all audits we have conducted, the average saving is 23% of the total bill. For a typical 10-line business account, that is £200-£350/month or £2,400-£4,200/year. Some businesses save much more. The largest saving we have found on a single audit was over £800/month for a company with 40 lines.

Do I need to change my phone numbers if I switch?

No. You keep all your numbers. When you switch network, your numbers transfer via the PAC code process. This is an OFCOM-regulated process that all networks must support. Your numbers will be ported to the new network within 1-3 working days, with minimal disruption.

What about business broadband. Can you audit that too?

Yes. We compare business broadband as well as mobile. If your broadband is slow or overpriced, we can often save you money by switching to a more suitable package. We recommend Sky Business Broadband SOGEA 80/20 at £35+VAT for businesses that need reliable connectivity for VoIP and video calls. The 20Mbps upload speed makes a significant difference.

How do I get started?

Call us on 0203 006 1011 or send us your bill online. We will have your audit results back within 24 hours. It is completely free, and there is no obligation to act on our recommendations. But when you see the numbers, you will want to.

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Stop Overpaying. Start Today.

Every month you do not audit your business mobile bill is another month of money wasted. Not lost, wasted. Paid to a network for services you do not use, phones you do not insure, and lines that belong to people who do not work for you anymore.

The audit takes 30 minutes if you do it yourself. Or one phone call if you let us do it.

You are a business owner. You would not pay a supplier twice for the same delivery. You would not keep paying rent on an office you have moved out of. So why are you paying for 20GB of data when you use 5?

Call us on 0203 006 1011 or get a free bill audit. We will tell you within 24 hours if you are overpaying, and by how much.

Compare The Networks . OFCOM-regulated, 4.3/5 Trustpilot, on your side since 2008.