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BT Mobile Family SIMs: our guide to how they work and their benefits

We review BT Mobile's Family SIMs, calculate the savings and discounts they offer and look at their advantages and disadvantages. SIM Sherpa is your trusty guide. Last updated: December 20th 2017

Essential guide to BT's Family SIMs

1) BT Family SIMs give you a quantity discount for taking out multiple contracts on one bill

Multiple BT Mobile SIMs

Genuine savings for taking multiple SIMs on one billCalculate savings

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 being loyal.

The basic idea is that you could have a SIM for every one of up to 5 members of a family, all paid by the same bill payer, and either managed by the main account holder, or separately by each SIM holder.

By adding more SIMs, you increase the size of the discount you’ll receive. Depending on current prices, we've seen this stretch all the way up to £660 over 12 months. That’s when you take 5 SIMs on BT’s largest plan.

At the moment we rate BT's Family SIMs as the best shared mobile plans available in the UK.

Useful link:
Here's BT's own official guide to Family SIMs
on their official website.

2) Family SIM savings can genuinely add up to £660 in a year

Savings on BT Mobile Family SIMs

The discounts vary by planSee the plans

The size of the discount you can achieve varies depending on the plan you opt for and the number of SIMs you take. The savings against regular BT Mobile prices usually range between about £84 and £660 over 12 months.

As a rule, the more SIMs you take, the bigger the discount. And the larger the plan you take, the greater the saving will be overall.

The largest £660 saving we found referred to taking the largest plan (typically 15GB) on 5 SIMs, over one year.

In general, BT Mobile SIMs are already well priced and sell very well on their own at a full price. For that reason SIM Sherpa can recommend that the discounts are genuine and do represent real value for money.

Useful link:
See very latest savings on each plan

3) Existing BT broadband customers also get their regular £5 monthly discount but Family SIMs are still open to anyone

The deals get cheaper if you have BT Broadband

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 month. And that’s on top of the Family SIM discounts themselves.

Useful link:
Learn what BT broadband customers are entitled to
in BT's official article.

4) New BT Mobile customers can get a BT Mobile Reward Card with their main plan on Family SIM

A BT Mobile Reward Card

A pre-paid Mastercard to spend practically anywhereHow to get one

BT Mobile really do throw big offers at new customers. And 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, rewarding you pre-paid Mastercard often loaded with up to £100.

If you join on one of the above plan types and add Family SIMs to your order at the same time, you'll still be entitled to exactly the same Reward Card offer. That means you'll 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).

One thing to remember is that only the first main plan on a Family SIM gets the reward, not the extra SIMs you add. So you may still want to see if joining on separate plans is better value to get multiple Reward Cards instead of the Family SIM discount.

Useful link:
Reward Card offers currently running on Family SIMs

The ins and outs of how BT Mobile Family SIMs work

Let's now take a look at these shared plans' features, benefits and any disadvantages they may have too:

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

Friends or family

Invite anyone to join your shared planHere's how

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.

6) 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

7) You do all have to be on the same plan though

All on same plan

You'll need matching tastes in mobile plan too!

It’s one of the few weaknesses of BT Mobile’s Family SIM plans; that everyone will need to join on an identical tariff that comes with the same allowance of minutes, texts and data to use each month.

This could be a pain if everyone in your group has differing needs. Imagine, for example, a teenager who watches videos on the bus every day so needs loads of data vs their dad, who may only want to send a few texts and make a few calls each month.

BT do have an answer to this though: you do have the flexibility to add more monthly minutes or data to individual SIMs within your overall account. And if it's really not working out, you can also drop any of the additional SIMs with just 30 days’ notice.

Useful link:
See costs for extra data or minutes add-ons
in BT's price list.

8) You don’t have to join all at once: existing BT Mobile customers can add Family SIMs whenever they’re ready

Adding a BT Mobile Family SIM

It's easy to add more Family SIMsSee how

A massive benefit with Family SIMs in general is just how flexible they are:

If you’re only just joining BT Mobile for the first time, there’s no pressure to take the extra SIMs there and then. You’re free to add them to your account at a later date. Either one by one, or multiple SIMs at once.

This is a really useful feature. Particularly if you know your children or friends are still currently in contract elsewhere but will be interested in joining BT Mobile down the line.

When they’re ready, you add a Family SIM by signing into your BT Mobile account and following the instructions under the link below. The discounts will automatically be waiting for you there.

Useful link:
How to add Family SIMs to your account later
from BT's help section.

9) The additional SIMs are on shorter 30-day contracts giving you flexibility to drop them if anyone decides to move on

Cancel a BT Mobile Family SIM

Wave goodbye with just 30 days' noticeRead the T&C's

Although the ‘main’ contract as part of a Family SIM deal is always either on a 12-month SIM only plan or a 24-month smartphone contract with BT Mobile, the additional Family SIMs are much more flexible:

They’re only ever on a 30-day term. And that’s a good thing because it means you’re free to add or remove additional SIMs to your account, according to what you need.

So if other people in your family aren’t out of contract yet, you can add them at a later date. Or if someone decides they’re ready to take their own contract elsewhere or with BT, you only have to give 30 days’ notice and you’re free.

Useful link:
Read all Family SIM terms and conditions
in BT's legal stuff section.

11) Roaming: Family SIMs get you free EU roaming

Roaming on BT Mobile Family SIMs

Roaming on each SIM can be managed separatelySee roaming costs

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, 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.

12) You can 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

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.

13) You can use a BT Mobile Family SIM in a locked EE phone

EE locked phone, BT Mobile SIM

No need to pay EE to unlock your phone

The overwhelming consensus on user forums on both EE’s website (and confirmed by an EE customer service agent) and BT customer forums is that BT Mobile SIMs do work perfectly in phones locked to EE.

Family SIMs are no different to any other BT Mobile SIM, so if you’ve bought an EE-locked phone or you’ve got friends or family coming to the end of a phone contract with EE, a Family SIM is a viable option for them.

It means you won’t have to pay an unlocking fee to EE to join BT Mobile.

Remember also that every mobile contract that you sign up to online is covered by the Ofcom requirement that you can return it 14 days later without penalty. So if you have any problems getting a BT SIM to work with any phone, you’ve got that re-assurance.

One other important reminder is that you must always continue to pay for contracts with other networks until they expire or pay a fee to leave earlier. Never just stop paying a contract, as this will harm your credit standing.

Useful link: Find your best SIM only plan on BT Mobile

14) Locked phones to Vodafone, O2 or Three: what to do

Locked phones from other networks on BT Mobile

Bring locked phones from other networks

Even if you’ve got a phone that’s locked to another network like Vodafone, O2 or Three, you can still join BT Mobile on a Family SIM. You’ll just need to take a couple of steps to get the handset unlocked.

On Three, all phones since 1st January 2014 have automatically come unlocked anyway but if your phone is locked to Three, you can get it unlocked by filling in this form at It’s totally free to do this.

Vodafone will also unlock a phone for free if you fill in this form but they do have a couple of conditions that you’ll have needed to have used the phone on their network for at least 30 days.

O2 need you to login to your account to unlock a phone on their network (see instructions here) and there are some conditions around Pay Monthly and Pay As You Go phones.

Again, we must stress that you need to keep paying any existing contract on another network until it expires and you cancel it, otherwise you may damage your credit history, which could make joining another provider harder.

15) BT Mobile Family SIMs will also work in tablets / iPads

BT Mobile SIMs in tablets

A BT Mobile chat agent confirms their SIMs work in tablets

You don’t just have to use the extra discounted SIM only plans for friends and family’s phones: if you have an iPad or a tablet, which takes a SIM card, you can use one of your extra BT SIMs to connect to 4G out and about.

This is according to a chat conversation with a BT Mobile representative on 25th April 2017 (see related screenshot) and also a help article on BT’s own website (read it here).

You’ll still be paying for minutes and text included in the monthly bundle that your tablet won’t be able to use but you will be able to make use of the monthly allowance of 4G data out and about on your device.

It’s worth noting though, that BT’s terms and conditions do explicitly say you can’t use their SIMs for mobile WiFi devices. These are portable devices which use a 4G SIM to create a WiFi hotspot for other devices to connect to.

Useful link: Read BT's terms and conditions on mobile broadband in their legal section.

16) You can’t officially use Family SIMs for business mobiles

BT Mobile business sharer plans

BT's business mobile offer shared plans tooSee options

Strictly speaking, all BT Mobile’s regular plans, including Family SIMs, are intended only for personal use.

BT’s terms and conditions state: “The service is just for you or your friends and family to use for your and their personal use (meaning that it shouldn’t be used for any trade, business or profession).”

That said, using personal mobiles for small businesses is a widespread practice, which is rarely actively prevented by mobile networks, particularly if your usage isn’t greater than regular consumers (e.g. you’re not sending out 10,000 spam texts a month).

For a Family SIM, your BT Mobile account does need to be set up using your personal details and billed to a personal bank account, which depending on how your business is structured could be a pain.

On the other hand, there may be benefits to taking out a ‘proper’ business tariff with BT Mobile, like more suitable billing, service guarantees and inclusive roaming you wouldn’t get with a consumer package through them.

Useful link:
See if a BT Mobile business tariff would work for you
in their dedicated section.

Sound interesting? Find a BT Mobile deal

Here are some useful links to find out more, if you like what you've heard about Family SIMs

Get a BT Mobile SIM only plan

BT Mobile SIM only deals


Reward Cards
up to
in value

See SIM only plans

Check BT Mobile's coverage

BT Mobile coverage checker

Use coverage checker

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

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

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