BT's minimum speed guarantee for business broadband

What is BT's minimum speed guarantee?

When you check BT Business Broadband at an address, BT gives three speed figures: an estimated download range, an estimated upload range, and a minimum guaranteed download speed. BT's formal name for the last one is the Minimum Guaranteed Access Line Speed, or MGAL. The figures are repeated in the order confirmation BT sends you, which is the place to look them up later.

The guarantee comes with every BT Business Broadband plan: Essential, Enhanced, Pro and BT Ultra Broadband. It is a commitment from BT about the access line to your premises. It is not a promise about Wi-Fi speeds in each room, about any one website, or about upload speed.

For the wider differences between business and residential services, see business broadband vs home broadband.

How BT works out the guaranteed figure

BT explains its method in its help pages. The minimum guaranteed download speed is based on the download speed that the 10th percentile of customers on the same broadband achieve at the business peak time, which BT defines as 12:00 to 14:00. Put simply, it is close to the slowest speed experienced by one in ten customers on a similar service at the busiest point of the working day.

The estimated download range is wider: BT takes the speeds of the 20th and 80th percentile of customers on the same broadband and adjusts them for congestion at the business peak. The upload range is worked out in the same way, but BT notes that the minimum upload speed is not guaranteed under the code.

Because the figure comes from real customers on the same product, it is realistic rather than optimistic, and that is the point of the code behind it.

The Ofcom Business Broadband Speeds Code of Practice

The guarantee comes from Ofcom's Business Broadband Speeds Code of Practice. BT's help describes it as a code that has existed since September 2016 and was revised on 1 March 2018. It is voluntary: not every provider signs it, and BT has signed it.

The code has two aims. The first is honest information: providers give business customers clear, realistic speed estimates when broadband is sold and afterwards. The second is a fair remedy: the code sets out how providers should manage speed problems, and gives customers a clear route out of the contract without penalty if download speed falls below the minimum guaranteed figure and is not fixed.

For a business, that turns the guaranteed figure from a marketing number into something with consequences. You know before you sign what speed BT commits to, and you know what happens if it is not met.

The right to exit, step by step

BT sets out the process for the right to exit in its help. All of these need to happen for the right to apply:

1. Your speed falls below the minimum guaranteed download speed for at least 3 successive days. Check the figure in your order confirmation and test properly; our BT Business Broadband speed test guide explains how.
2. You tell BT about the problem. BT says you can report it through its broadband speed checker or by contacting BT support.
3. The problem is identified as BT's fault. It must be outside the stabilisation period, and agreed to be BT's responsibility rather than, for example, your own Wi-Fi or equipment.
4. BT is unable to fix it within 30 calendar days of you reporting it.
5. You then have the right to exit. BT says you may cancel the broadband without penalty if it has not been able to provide the minimum guaranteed download speed within 30 days and any other options BT offers are not suitable.

BT's terms add two practical points: charges for service you have already received are still payable, and you must return any BT hub. Full details are in Ofcom's code and BT's broadband terms, and they apply as written at the time.

What else you can cancel with the broadband

A business rarely buys broadband on its own, so BT's help explains how the right to exit reaches other services:

• Services that depend on the broadband. If a BT service cannot work without the affected broadband, you may cancel it without penalty too.
• Bundles. Where broadband and another service were bought together, such as a broadband and phone bundle with a BT Digital Line, the right to exit applies to the products in the bundle.
• Not independent services. Services that work without the affected broadband, such as a mobile phone, are not covered.
• Only the affected line. If you have more than one broadband service, the right to exit applies only to the one that failed to reach its minimum guaranteed speed.

If your phones run over the same line, plan where your numbers would go before you exit. Our BT Business Broadband contracts guide covers the other ways a contract can end.

Before you report: the stabilisation period and Wi-Fi

Two things catch people out.

The first is timing. BT calls the first 10 days after connection the stabilisation period. The equipment is working out the best stable speed for the line, so speeds go up and down, and BT's right-to-exit process only counts speed problems outside that window. Test again once the 10 days have passed.

The second is Wi-Fi. The guarantee covers the access line, so a test over Wi-Fi from the far end of the building measures your Wi-Fi as much as your broadband. Test with a laptop plugged into the hub by cable. If the wired figure is healthy and Wi-Fi is the problem, the fix is coverage, not a fault report: see Complete Wi-Fi Plus, Smart Hub 3 and our business Wi-Fi guide.

If the line is genuinely slow, BT's normal fault service applies alongside the guarantee. See BT Business Broadband support for how faults are reported and how Prompt Care changes fix targets.

Questions to ask before you order

The guarantee is most useful before you sign, when it can still change your choice. When you compare options, ask for these for each tier available at your address:

• The minimum guaranteed download speed, not just the estimated range. If the guaranteed figure would not cope with your busiest hour, the tier is too small for you, whatever the headline says.
• The estimated upload range. Upload is not covered by the guarantee, so check the estimate carefully if you send a lot of data out.
• Whether Full Fibre reaches the premises. Full Fibre tiers carry much higher upload ceilings than Standard Fibre or copper; see BT Business Full Fibre.
• What else depends on the line. If phones, card machines or a Digital Line run over it, plan for what happens during a fault as well as a slow spell. Hybrid Backup keeps you online over 4G if the line fails.

We can put those figures in front of you as part of the quote, so you compare tiers on the numbers BT commits to.

How we help with speed questions

Before you order, we show you BT's estimated speed ranges and the minimum guaranteed download speed for each tier available at your address, so you can choose with the guarantee in view rather than the headline figure. If the guaranteed figure at your address looks too low for how you work, we can talk you through BT Business Full Fibre, Ultra or a leased line instead.

After installation, speed faults are reported to BT, which owns the guarantee and the fix. We can help you test properly and understand where you stand. Contact us to check the guaranteed speeds at your address.