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O2 custom plans explained: how they work, the benefits and downsides

O2 logo and magnifying glass

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We explain O2's new customisable phone plans, see what advantages they bring and calculate if certain combinations get you a better deal. SIM Sherpa is your trusty guide. Last updated: 5th August 2020

How O2's custom plans work

O2’s custom plans: what they’re about in a nutshell

O2 customisable phone plans banner

Tweak every part of the planRead O2's own guide

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For a long while now, O2 Refresh has allowed you to upgrade your phone early, without having to pay early termination fees or surrender your phone. They’ve now added more flexibility:

O2’s custom plans let you choose a contract length that works for lasting anywhere between 3 and 36 months. And you can also choose how much you’re willing to pay up front to lower the monthly cost.

They’ve also kept the early upgrades. And added the ability to switch between data plans from month to month, if your usage or budget changes. O2 call this flexing your data.

Below, we take a quick look at what the pros and cons of O2’s build-your-own custom plans are, and show you how to pick the right deal for your needs.

Useful link: O2's full length guide to custom plans

The benefits: build-your-own phone deal around your budget

A phone and contract option sliders

Play with the upfront cost and contract lengthSee the phones

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Once you’ve chosen your preferred phone from O2’s pay monthly range here, you can play with the settings for contract length, upfront cost and data allowance to create your custom deal.

Bring down the time it takes to pay off the cost of the device by choosing a shorter contract. This increases the monthly cost but brings forward the day when you can upgrade or switch networks.

Or choose a longer contract length to lower the monthly cost (because you’re spreading the total over more months). This means you’ll be tied to O2 and their usage plan for longer.

Playing with the upfront cost has similar effects. Increasing your contribution reduces the monthly cost. Decreasing it means your monthly bill will be higher but you don’t have to already have the money.

Useful link: Change the data in your plan month-to-month

Disadvantage: it's really hard to compare O2's phone prices

O2 custom plan calculator

Use O2's calculator on each phoneChoose a phone

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Our main problem with O2’s custom plans is that there are now so many combinations of upfront costs, monthly costs and data amounts that it’s really hard to compare prices and make a decision.

Per phone, there’s now 33 different contract lengths you can choose. And anywhere up to 100 different choices of how much to pay up front for your device.

Multiply those together and you end up with thousands of combinations for one phone alone. And each combination tweaks the monthly price you’ll pay.

So how do we consumers make sense of it and check if the combination we’ve chosen is the right one and we’re not getting a bad deal? See our best price combination section below to find out.

Useful link: See latest O2 phone pricing

Calculating the best prices

The total price of the phone always stays the same

Device cost slider and phone

Same total device cost, different contract lengthsO2's full guide

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It's worth understanding how O2's phone deals are structured before you start. They're made up two parts, a loan for your phone (paid off monthly until it’s gone) and a monthly plan with your mins, texts and data.

The total cost of the device on O2's custom plans always stays the same, no matter whether you split it over 3 months, 36 months or somewhere in between. Or if you pay some of its cost up front.

The monthly cost of your airtime plan (your minutes, texts and data) also stays the same, even if you fiddle with the device cost. It gets added on top to make your total price.

Once you know these two facts, it’s a bit of a relief:

There’s no magic combo of contract length and upfront cost where the total device cost falls, and you can’t get pick a ‘wrong’ combo and pay too much. So what are your options?

Useful link: Read all benefits to O2's custom plans

Shorter contract lengths: more flexible, higher monthly cost

A short contract option

You'll pay off the device in bigger chunks

It might sound obvious but if you choose a shorter contract length, you’re going to pay off the device cost more-quickly. And at that point you’re free to make your next move.

The phone is yours, and you can choose either to upgrade to a new phone (keeping your old one too) and take out a new phone deal, switch to SIM only, or leave O2 entirely.

It also means you’ll be tied in for fewer months paying O2 for the minutes, texts and data plan (you can’t leave this before you’ve paid off the device).

Obviously when you choose a shorter contract, the total cost of the phone is spread over fewer months, so this option does increase your monthly cost (although not the total cost).

Useful link: O2's help section on credit agreements

Longer contract lengths: reduced monthly cost, less flexible

Longer contract option

Spread the same cost over more months

If you play with the sliders, you’ll see that the shorter time you pick to pay of the phone, the higher the monthly cost will be. The monthly cost can get intimidating quite quickly.

So if you’ve got a particular monthly budget for your mobile phone contract, you can pick a longer deal that spreads the device cost over more time. More months means the monthly payment is lower.

It’s worth noting though that, by extending the amount of time you take to pay off the phone, you’re also tied in to paying the monthly airtime plan (mins, texts, data) too.

Because we’d argue O2’s plans tend to be pricier than other networks, you are making the total cost of the whole deal higher by missing the opportunity to switch to a cheaper deal earlier.

Useful link: Compare phone contracts from all networks

Our verdict on O2's custom plans

Best strategy: pick the shortest deal you can easily afford

O2 Pay Monthly phone range

Only pick a contract you can affordO2's phone range

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If the overall aim is to reduce the amount of money you pay to O2 over the course of your contract, it’s best to pick as shorter overall deal as you can afford on a monthly basis.

That way, even though the total device cost will stay the same, there will be fewer months where you’re tied to paying O2 for your minutes, texts and data. So the total combined cost is lower.

Do not stretch yourself though. You want a deal that’s affordable on a monthly basis. You don’t want ever to miss payments because you’re short of cash one month. This is bad for your credit rating.

The same applies for upfront costs. We’d aim to be borrowing as little as possible. Pay as much up front as you can afford. That way you’re on the hook for less for the rest of the contract.

Useful link: Pick a phone at

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