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What is Sim Free?

Friday 29th May 2009 by Andy Simpson in Mobile Phones, Mobile Technology.

There’s been quite a bit of confusion over the years about the terms “Sim Free“, “Unlocked“, “Dual Band” & “Unblocked“. They’re phrases we’ve all heard of, but just what exactly do they mean?

To understand these phrases it helps to have a slightly better understanding of how mobile phone pricing works.

When you buy a handset on either contract or pay as you go, your network will discount or subsidise the handset cost. Mobile phones cost a lot more than you’d expect, so when you take out a contract and get a free handset, some of your monthly line rental will go towards covering the cost of the phone. The same applies to pay as you go phones, the networks reduce the cost of the phone to encourage you to join their network and will then make that money back through your call charges.
The Networks know how long it will take for your line rental costs to cover the money they paid out on the phone – which is why over the last few years, we’ve seen contract lengths increase to 18 or 24 months as phones have become more expensive and sophisticated. With pay as you go phones, there is no line rental so they can’t guarantee they will make their money back, which is why you’ll always find pay as you go phones to be more expensive and often locked to the network you buy them on.

So, now you’re kind of up to speed on the thinking behind it all, I’ll try and answer your questions!

Sim Free:


What is Sim FreeThis is the phrase that is probably used the least, but is normally what people mean. Sim Free means exactly that – there is no Sim card included, it is just the phone (and any included accessories), because there is no network commitment here, the phone is not subsidised and will be the true value of the handset. As the handsets are not tied in any way to a network, any sim free phone can be used with almost all Sim cards (some won’t work on the 3 Network – see below). They have no network branding and will have the manufacturers original menu system on them. Buying your phone Sim Free can be a more expensive way of running a mobile phone, but handsets will often be available Sim Free before they are available through the networks, and with networks now doing much better deals on Sim only contracts, it can work out a cheaper, less restrictive way of running your mobile. All Sim Free phones sold by Mobile Fun are unlocked unless otherwise stated and will work with both contract and pay as you go sim cards.



Unlocked HandsetsAn unlocked handset can be the same as a Sim Free handset, but although similar in meaning to Sim Free, “unlocked” can be something completely different. The phrase “Unlocked” can refer to a handset that was originally sold on a network and was locked to that network – for example, most Vodafone handsets will only work with a Vodafone Sim Card. To use the phone on Orange for example, would mean that you would have to get the handset unlocked. By unlocking your handset, you remove this restriction and allow the phone to work with any network sim. Downsides to this are that “locked” handsets are normally network branded (the menu system will be configured for that one network) and some features may not be available or work properly. Unlocking a handset can sometimes invalidate your warranty, so its best to check with the manufacturer or network first. All Sim Free phones sold by Mobile Fun are unlocked unless otherwise stated and will work with both contract and pay as you go sim cards.

Unblocked HandsetsThis often gets confused with Unlocked. A phone will only ever become blocked for one of two reasons – The pin number on the sim card has been entered incorrectly 13 times, or the handset has been reported to a network as stolen. In either case you will need to contact your network in order for them to unblock your phone.


Dual Band:


Dual Band HandsetsSlightly more technical this one, but I’ll try to keep this as simple as possible! During my time in retail, a lot of people would come in asking if a phone was “dual banded” thinking that this meant Sim Free and open to all networks, but this is not the case. Dual band simply refers to the number of frequencies that a handset can work on. These days, every phone on the market is Dual Band, most are Tri Band and some are Quad Band! The theory is, the more bands the phone has, the more countries the phone will work in.

The confusion came in the UK with Dual Band when Orange and T-Mobile (One-2-One) launched in the late 90′s. Vodafone and O2, (Cellnet as was) worked on one frequency, and Orange and T-Mobile worked on another. Most handsets back then were single band and would only work on either Vodafone and O2 or Orange and T-Mobile, but not both. As technology moved on, phones started to become Dual Band – this meant that manufacturers only needed to make one handset, rather than two versions of the same phone. For various reasons, the networks began to introduce a network lock that prevented these phones from working on the other networks. So even though the handsets were Dual Band and worked on both frequencies – they would still only work on the network they were sold on unless the customer had the handset unlocked. Asking for a Dual Band phone, will get you a phone that works on two frequencies, but it won’t necessarily work on the network you want it to. Similarly, tri-band handsets works on three different frequencies, and quad-band handsets on four, but these handsets can still be locked to a network.

Pay as you go:


Pay as you go phonesBuying a Pay as you go phone, can be a cheaper alternative to buying Sim Free if you need to replace a handset without spending a fortune, but there are a few downsides that you will need to consider. Nearly all Pay as you go phones will be locked to the network they are sold on, so you’d need to buy your handset carefully. Most networks now insist on a minimum top up when you buy the phone, so the price you see may not be the price you end up paying. The handsets will be configured for Pay as you go, so some contract services may not work. Buying a phone on Pre-pay with the intention of using a different Sim Card, (Box-breaking) is against the terms of service for most networks, and can land you in trouble, so its normally worth checking with your network. Most networks will normally offer some kind of incentive if you want to upgrade, so its worth a call to customer services before you buy. Pay as you go phones, will work with contract sim cards, but you will need to change some settings in order to access Internet and Picture Message services.

3 HandsetsThree are the spanner in the works! They complicate things slightly when it comes to buying a Sim Free phone because when 3 launched their 3G network in 2003, they had the most advanced mobile network which ran on a different frequency to all the other 4. This lead to them having a more limited handset range and this made buying a Sim Free phone that worked on 3 nearly impossible. Over recent years, and as 3G has been rolled out to all networks, the handset range has increased as more and more phones now work on 3G networks – but not all Sim Free phones are compatible with 3G. Its very important to remember that if you are on 3, that you will need to buy a 3G handset. Popular phones like the Nokia 6300 won’t work, so always check before ordering that it will work on 3G (often listed as 2100/UMTS).

Related posts:

  • http://williamjudd.com/ William Judd

    It looks like Vodafone’s 4G network in Portugal is on bands 800, 1800 and 2600.


    Checking on GSM Arena, the One M8 supports all of these bands – so you should be just fine.


  • Saskia De Visser

    Hi there, If I buy a HTC m8 on a contract from vodafone (UK) would my Portuguese vodafone sim card work on this same phone when used in portugal ?

  • jacko

    My father is 86 and just needs a phone for calls and text He does not have internet. He tied himself into a contract which was not a good deal but it is coming to the end so I am looking for the cheapest deal for him. Could he just use his existing phone with a new basic contract or should he look for one with new phone It is so confusing with cash backs etc. He changed from Pay as you go to a contract because he did not want to keep topping up. He does not use it much, mostly when not at home for emergencies or when is in hospital etc. Are there any special deals for senior citizens with phone that are easier to use.

  • http://williamjudd.com/ William Judd

    It depends on which frequencies/bands your phone supports. Look up the phone you have on GSMArena, then check that against the bands that Airtel/Vodafone provide.

  • Preethi Raj

    I’ve got a UK Sim free phone, bought in the UK. I’m moving to India next month and I’m wondering whether I can use Airtel/Vodafone sim in India with my phone. Some people say I can’t use this phone in India for 3G and some say it won’t work at all. Why can’t I use a ‘sim free’ phone in India? Might be due to different bands/frequencies?? Please clarify.

  • Raj

    Great! Thanks.

  • http://williamjudd.com/ William Judd

    Yes, that should work!

  • Raj

    Can I buy a UK sim free phone and use Indian Sim card. The reason why I’m asking is I’m a visitor the UK and I’m looking to buy a phone here. Once I go back to India, I want to know if I can use the network sim cards in India with the sim free phone I purchased in the UK?

  • lavinia

    very useful thank you

  • http://www.facebook.com/david.hilel.1 David Hilel


  • http://williamjudd.com/ William Judd

    It should all work out, I wouldn’t worry about it :)

  • Chaz

    i want to buy a sony xperia tipo but its a sim free phone as they dont sell it on my network 3, will my 3 contract sim card work in this sim free phone, i checked the specifications on this phone and the phone runs 3G and it is listed as 2100/UMTS ?, i dont want to buy the phone and then the sim card dont work i spoke to my network provider they sed it wudnt be a problem but im not certain can anyone help? or has any 1 come accross the same sort of problem?

  • http://williamjudd.com/ William Judd

    Take it back to the store :) If it’s meant to be unlocked, then it should work. If it isn’t unlocked, you’ve been misled by the woman you spoke to.

  • oldy

    bought an Alcatel 3g phone from Tesco as the woman said it would work with 3.. got home and it says emergency calls only.. can anyone help?

  • ReiKarlo Esguerra

    hello! just wanna ask if “simfree” phones can have GSM-network sim inserted? Thank you.

  • Lousina

    Am new to MobileFun & found explanations really helpful. However, also newbie to smartphones and would appreciate suggestion as best to buy; want it to be sim-free as do not want to be tied to any network. Hope you can help because everything changes to quickly that I feel somewhat overwhelmed by technology – hard to keep on top of things.

  • http://williamjudd.com/ William Judd

    I’d recommend checking out giffgaff – you can get unlimited internet, unlimited texts and 250 minutes with a £10 goodybag. You can order two sims (for free) if you like, and on the second one get a data-only goody bag for the iPad.


  • Rick

    Great article, thanks. I am traveling to the Uk in May and would liken to buy a ‘Pay as you Go’ phone. Where do you get Sim cards and at what cost. Will be there 3 weeks and expect minimal use of the phone, guessing 40-50 calls max.
    Also have a iPAD, can I get a month 3G contract to use there?

  • pomodori1

    thanx buddy, it helpd me a lot

  • Dantheman

    you can get a phone that you can put two sim cards in or 3 sim cards in look on ebey and there are lots on there i got a phone where i put 3 sim cards in

  • Captain B

    Thanks William. That’s all I needed to know.

  • Anonymous

    That’s definitely the plan! You can even pick up a dual sim adapter for an iPhone 4 here:

  • Captain B

    I have two pay as you go phones. One I use in Spain (Vodafone Espana) and one I use in the UK (Vodafone UK). Both, obviously with different numbers. My question is. Can I buy one good smart phone, put both cards in it and switch from one to the other whichever country I’m in?

  • Captain B

    I have two pay as you go phones. One I use in Spain (Vodafone Espana) and one I use in the UK (Vodafone UK). Both, obviously with different numbers. My question is. Can I buy one good smart phone, put both cards in it and switch from one to the other whichever country I’m in?

  • Messssj

    thank you very much

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