Martin Lewis, the Money Saving Expert, appeared on ITV’s This Morning today to discuss his Quick Deals of the week which included the top SIM-only deals to reduce phone bills by hundreds in the year, how to get £5ish Odeon cinema tickets, and how to get a ‘free’ McDonald’s breakfast this Sunday.

He said: “This is the important thing to understand, there are only four mobile phone networks in the UK: Vodafone, EE, 02 and Three.

“Every other network (Asda, Tesco, Giffgaff) piggyback on their signal – they’re what’s called virtual networks.

“So if you don’t want to move network, what you can simply do and say is: ‘which company with the same signal has the cheapest SIM for me?'”

He revealed that a whopping nine million customers are out of contract in January on their mobiles, and many are still vastly overpaying despite being able to save hundreds on their mobile bill in the year by doing one simple thing; switch providers.

He said: “Lots of deals that easily give enough data and calls for most people cost less than £10 per month, and are across every main network.

“Remember, while there are many different providers, most piggyback off the main four networks, essentially borrowing their network space.”

So, an easy way to stay on the same network, without worrying about changes in signal, is to “take advantage of new customer deals” and switch to a network that piggybacks off the main four providers.

Here’s a rundown on what cheap SIM-only deals are available now across the four networks, according to the Money Saving Expert.

Three: iD mobile 1GB data, unlimited minutes and texts for £6 per month on a one-month rolling contract (it’s £5 per month if you go via many comparison sites including Compare The Market, Broadband Choices and Uswitch). Smarty – a no-frills Three sim – has 30GB data sim with unlimited minutes and texts for £10 per month, also a one-month rolling contract.

£5ish’ Odeon cinema tickets

Martin said: “Go online to deals site Groupon by Friday 6 March and you can get five Odeon tickets for £23.75 or two for £11.50 (factoring in the 75p per ticket booking fee).

“You don’t have to use all the tickets in one go and they can be used by different people – so ideal for families or a group of mates. They need using by 20 March and work with most 2D screenings barring some upcoming movies, eg, Bad Boys for Life and Dolittle, before certain dates – usually during their first week or so of release. Whether it’s a winner depends on your local Odeon as standard prices vary between £3 and £18.”

Free McDonald’s McMuffin this weekend

Money Saving Expert said: “Those who’ve downloaded the free McDonald’s app until Sunday 26 Jan can get its daily deals, where you can get discounted or even free food.

“The deals are available to new and existing users of the app. On Sunday 26 January you can get a free McMuffin (normally £2ish).

“For the freebies, you don’t need to buy anything else, just show the code which you’ll find in the app at the cash desk. Most but not all McDonald’s restaurants are participating – you can easily find out via the app whether your local one is included.”