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O2 SIM only deals 2023: Pick up an OUTSTANDING offer this December

This is your one-stop shop for the biggest O2 SIM only deals this December – we've collected them all below

O2 SIM only deals have a well-earned reputation for bagging you plenty of data for less, along with the ability to roam abroad at no extra cost. What’s more, the mobile network is also reliable and offers decent customer service. But which one should you go for?

To help you find the O2 SIM only deal that closest fits your needs, we’ve rounded up the best below into two categories: the best overall and the best on a budget. It isn’t an exhaustive list, but rather the offers that the SIM aficionados at Expert Reviews are happy to recommend.


This is our pick of the O2 SIM-only deals at the moment: 25GB of 5G data for an attention-grabbing £8/mth on a one-year contract. It’s an outstanding offer that comes with all of the usual unlimited text and minutes trimmings too, although bear in mind that the price may change during the plan.

Compare the best O2 SIM-only deals – LIVE!

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What’s O2 like as a mobile network?

Now part of a joint venture with Virgin Mobile, O2 is the UK’s second-biggest mobile network, surpassed only by EE. Despite its large subscriber base, O2 hasn’t fared well in recent Expert Reviews Mobile Network Awards, seeing a decline in customer satisfaction year after year. O2’s customer recommendation rate has dropped from 88% in 2021 to just 63% in the latest survey, placing it behind competitors.

O2 offers flexible pay-monthly smartphone contracts with customisable terms, though these can become less competitive over shorter periods. While providing a range of high-end to budget smartphones, O2’s 36-month contracts are more affordable than 24-month ones.

O2’s SIM-only plans, starting at £13/month for 1GB of data, offer value but can be more expensive than no-frills networks. The plans include interesting extras like subscriptions to streaming services and priority booking at O2 venues. The Unlimited Plus Plan, for instance, costs £35/month.

O2’s customer service is a concern, with less than half of the customers satisfied, according to our survey. While Ofcom’s research paints a less critical picture, there’s room for improvement. In terms of coverage, reliability, and speed, O2 ranks fourth among major UK networks. Its 5G rollout is ongoing, but current speeds lag behind competitors.

Roaming with O2 includes free EU roaming on most plans, with additional options for broader coverage. However, roaming charges can be high outside covered areas. O2’s Volt feature for Virgin Media customers and spending cap options add value to its offerings.

O2’s plans are feature-rich but come at a higher cost with slower speeds compared to rivals. While it offers advantages like EU roaming and venue perks, its customer service and network performance need enhancement. O2 received three stars out of five in our review, reflecting its mixed performance in the competitive UK mobile network market.

Read our full O2 review

So how do we find the best O2 SIM only deals for you? At Expert Reviews, we put a lot of thought into the offers we recommend and always want to get the most for your money. We’ve outlined our full deal-hunting strategy in a dedicated article, which you can read by clicking on this link.

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