Vodafone SIM Only Deals for Existing Customers: £5.25

Last updated: 27 October 2026

What is the best Vodafone SIM only deal for existing customers? As of 27 October 2026, Mobiles.co.uk is selling a 12-month Vodafone SIM only upgrade with 120GB of 5G data for £14 a month (£16.50 from 1 April 2027), and once its £120 cashback is claimed the year costs £63, or £5.25 a month on average. You keep your number, there is no PAC code to request, and you pay nothing upfront. The catch is that the cashback is by redemption, so you only get it if you send in your bills on time; if you forget, it is simply a £14 SIM. Before you sign anything, check your own upgrade date in the My Vodafone app, because a 12-month SIM only plan can usually be changed after three months and a phone plan only near its end date. This SwitchSquid guide compares the Vodafone upgrade SIMs listed on Mobiles.co.uk when we checked on 27 October 2026 with what Vodafone charges new customers, explains how the cashback claims work and shows when leaving is the cheaper move. We may earn a commission if you buy through links on this page; it doesn’t change the price you pay.

Sources: Mobiles.co.uk Vodafone SIM only upgrades, Vodafone upgrades help and Vodafone SIM only plans and price rises, all checked on 27 October 2026.

Can existing Vodafone customers get SIM only deals?

Yes. Vodafone sells SIM only upgrades to people already on its network, both directly and through retailers such as Mobiles.co.uk. An upgrade is simply a new contract on the same number: you choose a plan, the new terms start on your upgrade date, and your phone keeps working throughout. There is no PAC code, no new SIM card in most cases and no gap in service.

What changes is the price. Vodafone’s own headline SIM only offers, such as unlimited data for £26 a month on 24 months, are aimed at people joining. Existing customers usually see a different list when they log in, and retailers run separate “upgrade” tariffs with their own cashback. That is why the same 120GB allowance can cost very different amounts depending on where you buy it.

The quickest way to see where you stand is to open the My Vodafone app or log in at vodafone.co.uk, where Vodafone shows your upgrade date and the offers available to you. You can also call 191 free from your Vodafone phone.

When can I upgrade my Vodafone SIM?

It depends on the plan you are on now. Vodafone’s help pages set out three common cases:

• SIM only plans (Red or Airtime Xtra bought without a phone): you can usually upgrade from three months into the plan.

• Vodafone EVO phone plans: you can change your Phone Plan from month three, but if your Device Plan still has payments left, you either pay it off or keep paying it alongside the new plan.

• Older Essentials, Red Extra or Red Entertainment phone contracts: a “Flexi-upgrade” may be possible after six months; otherwise you upgrade near the end of your minimum term.

If you are already out of contract, you are paying the full monthly price for an allowance you could probably get for less. Ofcom’s rules mean your provider must send you an end-of-contract notice and show its best deals for you, so if you have had that letter, now is a good time to act.

Vodafone SIM only upgrade deals compared (October 2026)

These are the main cashback-by-redemption Vodafone upgrade SIMs listed on Mobiles.co.uk when we checked on 27 October 2026. Each includes unlimited UK minutes and texts and 5G data, with a maximum speed of 100Mbps. Prices rise each April by the amount shown. Mobiles.co.uk also lists versions with automatic cashback or no cashback at all; see How the cashback works below.

Totals are the retailer’s own figures and already include the April 2027 rise. The standout is that 120GB and 70GB cost exactly the same over the year once cashback is paid, £63, so unless your bank balance is tight in the first few months, the bigger allowance is the better buy.

How the cashback works, and how not to lose it

All of the deals in the table above use “cashback by redemption”. That means Mobiles.co.uk does not knock the money off your bill. Instead, you pay Vodafone the full monthly price, then claim the cashback from Mobiles.co.uk by uploading copies of your Vodafone bills during set claim windows. The money then arrives in instalments.

Three habits make the difference between paying £63 and paying £183:

1. Write down the claim months on the day you order. They appear in your Mobiles.co.uk account. Put each one in your phone calendar with a reminder a week early.

2. Download every Vodafone bill as a PDF. The claim needs the bill that shows your number and plan, so keep them in one folder.

3. Do not change plan during the claim period. Moving to a different tariff can break the link between your bills and the cashback offer.

If you know you will not do this, look at the plans with nothing to claim. When we checked on 27 October 2026, Mobiles.co.uk also listed the 70GB plan with £55 automatic cashback, at £104 for the year after cashback, and the 120GB plan with £75 automatic cashback, at £108. Automatic cashback is processed for you, with no bills to upload. There were also plans with no cashback at all: 16GB for £7 a month (£93 in total) and 50GB for £8 a month (£105).

Is it cheaper to stay with Vodafone or leave?

For most existing customers in October 2026, staying and upgrading through Mobiles.co.uk is hard to beat on cost, as long as you claim the cashback. £5.25 a month for 120GB on Vodafone’s own network works out at about 4.4p per gigabyte. Few SIM only deals on any network go lower on cost per gigabyte.

Leaving can still make sense in three cases:

• You want no contract. All the upgrade deals here are 12 or 24 months. If you might move abroad, change phone often or simply dislike being tied in, a 30-day SIM costs more per month but lets you leave at any time.

• You want no cashback admin. A plain low monthly price with nothing to claim suits some people better, even if it costs a little more over the year.

• Your signal is poor. No price makes up for dropped calls at home. Check Vodafone coverage at your address first; if it is weak, a SIM on another network will serve you better.

If you decide to leave, text PAC to 65075 to get your code and give it to your new provider, who will move your number across. Our PAC code guide explains the steps and timings.

Vodafone’s April price rises explained

Since January 2025, Ofcom has required mobile providers to show annual price rises in pounds and pence when you sign up. Vodafone’s pay monthly airtime plans rise by £2.50 a month every 1 April, which is why every plan in the table shows a higher price from April 2027 and, for 24-month plans, again from April 2028.

Because the rise is a fixed amount, it hits cheaper plans harder in percentage terms. A £10 plan going to £12.50 is a 25% increase; a £16 plan going to £18.50 is about 16%. That is another reason the 120GB deal stands out: the total for the year is already in the £183 figure, rise and all.

How to upgrade your Vodafone SIM step by step

1. Check your upgrade date. Open My Vodafone or call 191. Note whether you still have a Device Plan to pay off.

2. Check your data use. The My Vodafone app shows how much you used in each of the last few months. If you rarely pass 20GB, the 70GB plan is plenty; if you hotspot a laptop, look at 200GB.

3. Choose the plan on Mobiles.co.uk and select the upgrade route, not “new customer”.

4. Confirm your details. Mobiles.co.uk will ask for your Vodafone number and account details so the upgrade goes on the right line. A credit check applies.

5. Diary the cashback claims. Do it the same day, while the order confirmation is in front of you.

6. Watch for the start date. The new price usually starts on your next bill after the upgrade is processed.

Other Vodafone-network SIMs worth knowing about

Several brands run on Vodafone’s network, including VOXI, Lebara, Talkmobile, Asda Mobile and Sainsbury’s Mobile. They use the same masts, so coverage is broadly the same, but features such as 5G, roaming and Wi-Fi calling can differ. These brands are mostly 30-day or 12-month plans with no cashback, which makes them simpler but rarely cheaper than £5.25 a month for 120GB.

Moving from Vodafone to one of these brands still needs a PAC code, because it counts as switching provider. If you are comparing across networks, our guides to Vodafone SIM only deals for new customers, the Vodafone 120GB cashback plan and EE deals for existing customers set out the alternatives. There are matching guides for O2 and Three customers too.

Fit summary

• Good fit for the 120GB upgrade: you are happy with Vodafone’s signal, use a fair amount of data and will claim the cashback.

• Good fit for 70GB: you want a lower monthly bill than the 120GB plan before cashback arrives, at the same £63 total.

• Good fit for 200GB: you tether a laptop or tablet regularly or stream a lot away from Wi-Fi.

• Consider leaving instead: you need a rolling 30-day plan or have weak Vodafone coverage at home.

Want a second opinion? Squid AI, SwitchSquid’s AI assistant, can help you work out how much data you really need before you pick a plan.

Important conditions

• Upgrade deals are for existing Vodafone pay monthly customers who are eligible to upgrade. A credit check applies.

• Cashback is by redemption from Mobiles.co.uk, not Vodafone. You must claim within the set windows, using your Vodafone bills; missed claims are not paid.

• Monthly prices rise by £2.50 each 1 April, as shown in the table.

• Maximum speed on these plans is 100Mbps.

• Prices and cashback were checked on 27 October 2026 and can change at any time.

FAQ

Do Vodafone give existing customers the same deals as new customers?

Not always. Vodafone’s headline SIM only offers are usually for people joining, and existing customers see their own list in My Vodafone. Retailers such as Mobiles.co.uk also sell dedicated upgrade tariffs, and as of 27 October 2026 their 120GB 12-month upgrade costs £63 for the year after cashback.

What is the cheapest Vodafone SIM only deal for existing customers?

On 27 October 2026, the lowest cost after cashback was £63 for 12 months, which applied to both the 120GB plan at £14 a month and the 70GB plan at £12 a month on Mobiles.co.uk. If you would rather not claim anything, the 70GB plan with £55 automatic cashback came to £104 for the year, and the lowest monthly price was £7 for 16GB with no cashback (£93 in total).

Can I upgrade my Vodafone SIM early?

If you are on a SIM only plan, Vodafone says you can usually upgrade from three months in. On an EVO phone plan you can change from month three, but you must keep paying or clear the Device Plan. Check your exact date in the My Vodafone app or by calling 191.

Do I need a PAC code to upgrade with Vodafone?

No. A PAC code is only needed when you move your number to a different provider. Upgrading keeps you with Vodafone on the same number, so there is nothing to request.

How does Mobiles.co.uk cashback work on a Vodafone upgrade?

You pay Vodafone the full monthly price, then claim the cashback from Mobiles.co.uk by uploading your Vodafone bills during set claim windows. The money is paid in instalments after each successful claim. If you miss a window, that part of the cashback is lost.

How much will my Vodafone SIM go up in April 2027?

Vodafone pay monthly airtime plans rise by £2.50 a month on 1 April each year. A £14 plan becomes £16.50 from 1 April 2027, and 24-month plans rise again in April 2028.

Is it better to upgrade or switch away from Vodafone?

If Vodafone’s signal is good where you live and you will claim the cashback, upgrading is usually cheaper, at £5.25 a month on average for 120GB. Switching makes more sense if you want a 30-day plan, have weak coverage, or would rather not manage cashback claims.

Final decision card

For most existing Vodafone customers, the 12-month 120GB upgrade through Mobiles.co.uk is the one to beat: £14 a month, £183 for the year, and £63 once the £120 cashback is claimed. The 70GB plan reaches the same £63 with a lower monthly bill, and 200GB costs £75 after cashback for heavy users. Check your upgrade date in My Vodafone first, then diary the claim months the day you order.