If you have been on the same network for some time - even just a year - you could be paying much more than you need to.

Here's our guide to help you to switch to a new mobile network.

Moving to a new network

Competition is intense between UK networks, and that's great news for you, because to compete with each other they're continuously updating their tariffs to offer you more than the competition. 

The information in this guide refers to Pay As You Go sim cards. Pay As You Go is also known as Pay and Go, Prepay, or the acronym PAYG. We'll use PAYG for the remainder of this article. 

Why move?

If you're already familiar with switching to a new mobile network, go to our SIM SELECTOR which is designed to help you to choose the best tariff for your needs.

You might have been on the same network for years, or you may have only been there for a few months. The beauty of PAYG is that you're not tied to any one network for any length of time. In fact, you can move at any time. 

Unfortunately the days of not having to top up until you used up your credit are all but gone (but there are a few alternatives which I will discuss later). These days, your phone top up will generally last for 30 days.

However, it's not bad news as the latest tariffs, or plans, give you a huge amount for your money compared even with just a few years ago due to the strength of competition.

How it works

Here's a quick summary of how today's plans work:

  • PAYG sims give you a set allowance of minutes, text messages and internet data to use on your mobile phone.
  • Top ups last for 30 days or until you use up the allowance, whichever comes first.
  • There is NO obligation to top up at the end of the 30 days, but you wont be able to make calls or send texts again until you do.
  • You can add your next top up before the current 30 days is up. This gives you continuous service. 
  • If you do not top up you will not be able to make further calls, texts or have any internet use until you do, but you will still be able to receive calls, usually for up to 2 months. 
  • If you do not top up for 3 or more months your number will be disconnected and you will lose the number. 

The important thing to understand here is that if you do not top up for several months (usually 2-3 months) the network will deactivate the sim card and your number will be disconnected. Once this is done, your number will be lost forever.

Keeping or transferring your mobile number.

If you want to keep your current number but switch to a new PAYG sim card, you can do so by transferring the number to the new network. You can transfer your number (before your current sim is disconnected) at any time. To do this, you need to obtain a PAC code from your network and give it to your new network.

You have a legal right to transfer your number at no cost to you. If you have any remaining credit, this is not transferable. 

See our guide on TRANSFERRING YOUR NUMBER for more details.

If you prefer you can have a new number when you get a new sim card. this will automatically be provided to you by the new network, you do not need to do anything (some networks may ask you to register a few details with them online and will then issue your number). 

Why it's important to top up your sim card

It is important to top up your sim card as soon as you get it. This is known as activating your sim. Insert the sim into your phone, make sure you have a signal then follow the instructions below. 

See our guide to ACTIVATING YOUR SIM for more details

If your sim is not activated, sooner or later the network will cancel or "deactivate" it. The sim is then classed as "expired" and you will lose your number. See the guide for more information on this. 

Topping up your Pay As You Go sim card.

This information is also shown on the "Activate your sim" guide.

You can top up your sim card by one of the following methods:

  • Buy a top up voucher at most supermarkets, filling stations and smaller stores such as newsagents and general stores. You then call a number supplied by the network and enter the number on the voucher, known as a "Top Up Voucher Number". 
  • Online via the network's own website - but be wary of independent sites that charge you extra to buy your top up. If you spend £10 you should get £10 of credit, no more, no less.
  • Buy a top up from an ATM - "Hole in the wall" cash machine - but be wary of the machines that charge a cash withdrawal fee as they may class a top up purchase as a cash withdrawal.
  • Top Up by credit or debit card over the phone via the network's helpline number, which will be shown in your sim pack. Some networks also allow you to top up a different mobile on the same network, such as your kids' mobiles. 
  • Did you know! Most networks now accept automatic monthly payments by card or direct debit, and may offer you extra for doing so. 

    This is intended as a guide only and do note that not all methods will be available to all networks. 

    I hope this guide has been helpful to you, but for further advice please contact your network directly. If you think any of the information provided is incorrect or out of date please let us know. There is a "Contact us" form link at the foot of the page. 

    But we're not quite finished...

    I don't want to top up every month! 

    You may not want to top up your sim card every month, especially if you're a light user, need a sim for mostly incoming calls, or a sim card for a vehicle tracker. 

    There are a couple of alternatives. Take a look at these. The O2 Classic sim is still available at the time of writing, but it no longer being issued by O2 and they're going fast. 

    O2 CLASSIC Pay As You Go sim card

    Or there's the GiffGaff sim, which allows you to simply top up without choosing a plan or tariff. You'll then pay their standard call rates, but do not have to top up every month. GiffGaff also runs on the O2 network.

    GiffGaff Pay As You Go sim card

    That's all for now folks! Don't for get to check out our SIM SELECTOR to help you choose the right Pay As You Go plan for you.