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BT Mobile Family SIMs:
all the benefits and disadvantages

BT Mobile plans from £5 a month

The retailers featured on this page may compensate us when our readers follow links to their websites and make a purchase. More

We review whether it's worth taking one or more of BT Mobile's Family SIM plans, looking at the discounts and other benefits they offer. SIM Sherpa is your trusty guide. Last updated: 27th March 2019

Our verdict on Family SIMs

Decent savings, short contracts but everyone's stuck on the same plan  (3/5, good)

BT Mobile Family SIM banner

Go to

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"There's no doubt that groups of friends and families can make genuine savings with BT Mobile's Family SIMs, compared with joining BT separately. And short 1-month deals give you some welcome flexibility.

But it can be hard to calculate up front how much you're going to be saving, as there's no straightforward way to compare. The biggest achilles heel is that everyone has to join on exactly the same data plan.

Overall, we think Family SIMs will work for a lot of people. But the key is to work out if you're definitely saving anything before adding more SIMs to your account. Or if you're better taking separate deals elsewhere."

Useful link: Latest Family SIM prices

In the rest of this guide

Here's what we've considered for our overall rating

The savings via BT's Family SIMs

Family SIMs give you a quantity discount on multiple deals

Build a bundle screenshot

Play with BT's calculator to find savingsBuild a bundle

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The easiest way to understand BT’s Family SIM is to think of it as getting a bulk discount for taking out multiple mobile contracts. A bit like a multi buy offer at a supermarket. It’s a reward for spending more with BT.

The basic idea is you have one billpayer for up to 5 mobile deals on the same account. And each time you add a new SIM, you get an additional saving vs the cost of buying them separately.

One of the downsides of Family SIMs is that's it's pretty hard to tell what the savings on individual plans are up front. By taking 5x SIMs, you'll typically save between 10% - 20% (depending on current prices and offers).

Each SIM in between saves you a bit more. But the discounts aren't evenly spread out - there's no uniform jump between each SIM but you can fiddle with BT's build a bundle feature to find out.

Useful link: BT's build-a-bundle calculator

Typical savings can vary between £2 and £26 per month

Family SIM savings estimate

Examples only, not actual pricingSee current prices

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As we've said, it's pretty hard to estimate up front how much you'll save via BT's Family SIMs, because it depends on the latest prices and any offers running. We can't provide any guarantees.

At the time of writing, we found a minimum total discount of £2 a month by taking a bundle of 2x SIMs. And a maximum total discount of £26 taking 5x SIMs on one of the largest plans.

We've noticed that the better the initial price for the main plan, the smaller the discounts for adding additional SIMs. So plans featured in sales and promotions attract smaller, further Family SIM discounts.

In a real-life user test, we also found that if you'd got a really good deal when you first signed up, you couldn't actually add extra discounted Family SIMs, without re-contracting onto a more-expensive main plan!

Useful link: See latest Family SIM prices

BT broadband customers get their regular £5 discount too

A BT broadband hub

BT Plus customers get double data tooWhat is BT Plus?

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Most BT Broadband customers will now be aware that they are entitled to a £5 monthly discount on any pay monthly plan they take from BT Mobile. This counts for SIM only and smartphone plans alike.

With Family SIMs, it’s exactly the same. Each additional SIM comes with a £5 discount compared to the price that someone without BT Mobile would pay.

That means, if you have BT Broadband and took 5x SIMs on any plan, you’d typically save £300 over the course of 12 months. And that’s on top of the Family SIM discounts themselves.

If you've signed up for BT Plus, you'll also get the same double data benefits and extra 4G speeds on Family SIMs that you get on every regular BT Mobile plan too.

Useful link:
All BT broadband customers benefits

Where to next?

The benefits of BT's Family SIMs

Short 30-day contracts you can add or drop at any time

BT Mobile app preview

Use the app to manage your SIMsSee app features

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Other than the discounts, one of the most useful benefits is that each of the additional plans is only on a 30-day contract, even if your main deal is a 12-month SIM or a 24-month phone contract.

That leaves you with the flexibility to pick up and drop extra SIMs whenever they're needed. And you don't have to take them immediately when you first sign up to BT Mobile.

So if you've currently got separate contracts elsewhere, you can add them to your BT account as and when they come up for renewal. And if anyone finds their fed up on BT, they can leave easily too.

Or say you're waiting for a new phone to come out, you can add a Family SIM to your account while you wait and then jump ship to another provider whenever you're ready. For us, flexibility is always a good thing.

Useful link: BT's app lets you manage your SIMs

Totally new BT Mobile customers can get a Reward Card

A BT Mobile Reward Card

A pre-paid Mastercard with money on itHow to get yours

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If you’re joining BT Mobile for the first time on a 12-month SIM only plan or 24-month smartphone contract, there will often be a BT Reward Card offer running (a pre-paid Mastercard loaded with money).

If you join on one of the above plan types, you can add Family SIMs to your order at the same time and still be entitled to claim the Reward Card - meaning you can get the Family SIM savings and the pre-paid card.

The value of the Reward Card is usually worth around 2-4 months of the monthly cost of a single SIM only plan. So is a healthy way of clawing back money from your deal (here's our guide on how to claim yours).

Only the first, main plan on a Family SIM gets the reward, not any extra SIMs you add. So joining on separate plans may sometimes be better value by claiming multiple Reward Cards instead of the Family SIM discount.

Useful link:
Reward Card offers currently running on Family SIMs

Everyone gets their own minutes, texts and data to use

No sharing with BT Mobile Family SIMs

There's no data sharing on Family SIMs

Some of the other networks have offered shared / family plans before and there was always one downside with them: you were given a monthly amount of minutes, texts and data, which you had to divide up between you.

This can actually be more bother than it’s actually worth: think how much each member’s mobile usage could change each month, and it could quickly become a pain to keep dividing this up yourself.

BT Mobile’s Family SIMs do away with that nonsense and keep things simple.

Everyone gets their own minutes, texts and data to use each month, so everyone knows what they have.

Useful link:
Compare the plans available as Family SIMs

You don’t actually need to be a family to share the plans

Friends or family

Invite anyone to join your shared planHow to add people

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Although it’s called a Family SIM, you don’t actually have to be a family to share BT Mobile plans and enjoy the savings: any group of people who know each other can take them up. This opens up possibilities.

You could be a group of friends, student housemates or colleagues who all want to enjoy the discounts. They can even already be on BT Mobile and join their account to yours to pay less.

The key though is, you’ll need one person who acts as the main account holder, who is responsible for paying all the bills and managing the plans.

For this reason, we’d always recommend that you know and trust the people you join on a Family SIM with.

Useful link:
How to invite people to join your Family SIM
according to BT.

Roaming: Family SIMs get you inclusive EU roaming

Roaming on BT Mobile Family SIMs

Roaming on each SIM can be managed separatelySee roaming costs

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Roaming on Family SIMs works identically to regular BT Mobile phone and SIM only contracts:

You'll get roaming in the EU countries listed here included at no extra cost, meaning data used for browsing plus minutes and texts to UK numbers come out of your regular monthly allowances.

If you’re travelling to the USA and numerous other destinations, you can buy a block of data to use while you’re there for a fixed cost (see the latest costs of data passes here).

Or in other countries, and for calls and texts, you’ll pay for what you use, as you use it (per min, per text, per MB). You can find the latest roaming costs in BT’s tariff guide under the useful link below.

Either way, on a Family SIM, the costs are the same and roaming works the same. Each SIM can roam separately and any charges that are incurred will be added to the main account holder’s bill.

Useful link: See a full breakdown of roaming costs in BT's tariff guide.

Transfer your old mobile number to any of the Family SIMs

Keep your number on a BT Family SIM

Everyone can bring their number with themLearn how

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Most of us want to stick to our current number when we change mobile deals. Fortunately, it's no harder to do this on BT's Family SIMs than on any other deal. Here's what to do:

Order your Family SIM from BT - this will come with a temporary number.

Then ring your old network and tell them you want a PAC (porting authorisation code). Once you have that, go to, login and give BT your PAC code.

They'll sort out the transfer, normally within a working day, and you'll still be able to use the SIM in the meantime.

If you've taken multiple SIMs, just repeat the process for each one.

Useful link: Read how to keep your number in BT's step-by-step guide.

Where to next?

The disadvantages of BT's Family SIMs

You all have to be on the same plan - this could be a problem

Two boys staring at mobile phones

Realistically people may need different plansCompare separate deals

here at
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The biggest weakness of BT Mobile's Family SIMs could be a killer for some people. You all have to join on a plan with the same amount of minutes, texts and data. You can't pick different ones each.

So if the main account holder is on a 4GB plan, everyone else has to be too. Given that everyone's data usage is different, this could quickly become a problem with people running out or never using up all their data.

There's no facility to share out unused data on BT Mobile (there is on EE with their clever data-gifting feature), so getting a Family SIM is only going to work if you and your family have similar usage habits.

If you don't, you could find out you're better off taking individual deals with the right amount of data, so use our SIM only price comparison tool here first. Although remember you'll then have to manage separate accounts.

Useful link: Costs for adding extra data

You could be better off joining on separate plans still

BT Mobile SIM only deals


Reward Cards

Rewards may be bigger than Family SIM discountsSee current rewards

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If you're extremely savvy, willing to commit to longer 12-month deals and join at the right time, you could actually still be better off by joining on separate 12-month deals. This won't be for everyone. Here's why:

BT Mobile almost always have pre-paid Reward Card offers running on their regular 12-month SIM only plans (see our guide). The reward values change weekly and can be worth multiple months of the basic plan cost.

Sometimes, the value of the reward will outstrip the saving you'd get by adding a plan as a Family SIM over the course of 6 months (imagine a family plan was £2 a month cheaper vs a full-price one with a £40 reward).

This varies week-to-week and plan-to-plan, so we can't say for certain this will always be a winning strategy. But it's worth checking both options to make sure you're getting the best price.

You'll need to start a new mobile account each time, because you don't qualify for the Mastercard with an existing BT Mobile account. And you'll need to remember to claim the card too (else it's pointless).

Useful link: How to claim BT Reward Cards

Where to next?

Alternatives to BT's Family SIMs

EE probably have the closest scheme to BT's Family SIMs

EE logoEE data gifting banner

10% discount and share data on EESee EE family plans

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Out of all the shared family plans we rank in our guide here, it's EE who have the nearest alternative to BT's Family SIMs. Their equivalent has some advantages and disadvantages:

Firstly, you'll get a uniform 10% of the regular price of any pay monthly product you add to your main account on EE. That can be a phone contract, a SIM only deal or even tablets or mobile broadband.

Depending on how many people you're planning to add, the savings can be more or less than BT as a percentage. But it's worth noting EE's deals are typically more expensive than BT in the first place.

So you can join on more types of plans and you don't have to take the same amount of data on each either. There's also an excellent data gifting feature that lets you move data around users on the same account if someone runs out and others have some spare.

Useful link: All features of EE's shared family plans

Where to next?

Our other BT Mobile articles and guides

Full review of BT Mobile

BT Mobile logo

Read BT Mobile review

BT Reward Card offers

BT Mobile Reward Cards

See latest Reward Card offers

Comparing BT Mobile & EE

EE vs BT Mobile

Read differences between EE & BT Mobile

How BT Mobile & Three compare

BT Mobile vs Three

Read BT Mobile vs Three comparison

Other relevant guides

Best shared mobile plans

Shared Family plans

See who we rate best

SIM Sherpa can help you find your next SIM only deal

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