The main advantages of a SIM only contract are:

Cost – SIM only is much cheaper than a standard mobile phone contract because with SIM only you are simply paying for the SIM card itself (this costs a few pence to manufacturers) and the tariff itself. Whereas with a standard phone contract you typically get a free (or heavily discounted) mobile phone as well as a phone tariff. By taking a SIM only plan the supplier is not having to provide a heavily subsidised smartphone as part of your contract therefore the costs savings are passed on in the form of low monthly charges for their SIM only deals. 12 month SIM only deals are the cheapest mobile phone plans that are currently available.

Convenience – If you already have a phone that you are happy with you just need to put a new SIM card into it once you sign up to a SIM only deal. This means you don’t have to learn how to use a new phone, move your contacts over, etc.

Flexibility – You have the flexibility of choosing a contract length that suits you. If you don’t like to be tied down to a contract then you might want to choose a 30 day contract which would mean you only need to give 30 days’ notice to cancel. This can be handy if you need a good tariff to continue using your phone but you want to upgrade to a new mobile phone deal in the near future when a top of the range phone comes out – cancelling your current 30 day SIM contract is easy!

Choice – You are certainly not short of choice when it comes to SIM only deals. There are hundreds of deals to choose from at all price points from all the major phone networks and online mobile phone shops. Look out for exclusive online tariffs that could save you even more!

The following type of people may want to consider opting for SIM only:

• People that have had previous mobile phone contract applications declined (a SIM only contract should be easy to obtain than a standard mobile phone contract).
• Students whose finances could be tight and vary from one month to the next may want the flexibility of a 30 day contract so that they could cancel the contract at short notice if money was tight.
• SIM only deals are a great way towards going to help repair a poor credit file (see more details below).
• If you are happy with your current mobile and don’t need a new phone as part of a contract.
• If you have been denied a standard phone contact it is possible that by taking on a SIM only for several months you would be able to prove to the mobile network that you manage your bills responsibly and this will work in your favour if you apply with that same network for an improved deal or contract that includes a free phone or free gifts.

The two main length of contracts for SIM only are 30 days and 12 months. There are a small number of 6 month deals and 24 month deals but the main choice will be between 30 days or 12 months.

If you opt for a 30 day contract you basically sign up to a rolling deal that will continue each month (you don’t need to renew it each month it just continues to carry on until you want to change it). If you decide for whatever reason that you want to stop the contract you simply need to give 30 days’ notice that you want to terminate the contract and once the notice period has elapsed your contract will end with no penalty fees and you will be free to look for another more suitable SIM only contract.

A 12 month contract means you are tied into a SIM only deal for the full 12 months. If you decide to end the contract early you would need to pay the difference that is owed on the contract to the supplier. These deals are obviously less flexible that the 30 day contracts but on the positive side because you are tied into a contract for a longer term and the network can account for 12 months’ worth of business from you, the 12 month deals are cheaper than the equivalent 30 day deals – often by several pounds per month.

We can narrow it down to one of three – the nano SIM, micro SIM or the standard (sometimes called a combi SIM). In order of size, the standard SIM is the largest SIM card, the micro SIM is about half the size of the standard SIM and the smallest of them all is the nano SIM.

If you are unsure about which size SIM your phone currently uses you can check the box or instructions that came with the phone, check the specifications of the phone online to see the SIM type or you could take the SIM out of the phone and examine the size yourself.

As a rule, you should expect these phone types and manufacturers to take each type of SIM card:

Nano SIM – Since the Apple iPhone 5 all subsequent Apple phones have used the nano SIM so that means the iPhone 5, iPhone 5c and iPhone 5s. The Motorola Moto X uses a nano SIM as does the ASUS PadFone Infinity and Nokia Lumia 1520. Tablets such as the iPad Air and iPad Mini also use the nano SIM card.

Micro SIM – If you have a smartphone or tablet that was launched after around 2010 and it is not included in our list of nano devices then it is highly likely that your device will take a micro SIM card. This includes the vast majority of Android phones and tablets as well as older Apple devices such as the iPhone 4 and iPhone 4s.

Standard SIM – Any phone that is not covered by the descriptions for nano and micro SIMs will likely take a standard SIM.

Generally SIM contracts are split by the type of SIM card – standard (combi), micro or nano and that is what determines which SIM contract is applicable for each device but there are SIM deals that cater to specific devices.

For example, if you own a BlackBerry phone there are SIM only deals for BlackBerry that include BlackBerry Mail and BlackBerry Messenger (BBM) included free of charge and there are iPhone SIM only deals.

You can get a SIM only deal from the following mobile networks –

• EE
• O2
• Three
• Orange
• T-Mobile
• Virgin
• Vodafone
• Tesco Mobile
• GiffGaff
• Talk Mobile
• Shebang

As well as being able to get SIM contracts direct at the networks you are also able to get them via online mobile retailers. Sometimes these providers offer Internet exclusive deals with some networks so they are well worth checking.

You will see SIM only contracts on the Denied.co.uk SIM only comparison engine from the following –

• buymobiles.net
• mobiles.co.uk
• e2save.com
• onestopphoneshop.co.uk
• mobilephonesdirect.co.uk
• phones4u.com
• carphonewarehouse.com
• affordablemobiles.co.uk
• dialaphone.co.uk

f you have struggled with bad credit in the past then you would likely stand a better chance of being accepted for a SIM only contract than you would for a standard mobile phone contract. The reason for this is as part of a mobile phone contract you will often be offered a free mobile phone so the supplier needs to be sure that you will be able to pay your phone bills because if you stop paying your bill soon after receiving your free phone the supplier will lose money. Therefore, standard mobile phone contacts require fairly stringent credit checks in most cases.

SIM only deals do not include a free mobile phone and as such there is less risk in offering a SIM only contract to a customer than there would be if there was an offer of a free phone attached. So it is understood that SIM only contracts are easier to obtain for a person with bad credit than standard mobile phone contracts.

There are also some providers such as Shebang that will offer 100% guaranteed SIM only deals which means people that have very bad credit will be guaranteed to have their SIM only contract application approved.

A SIM only plan can be a significant step towards improving a bad credit rating. This is because being accepted for a 30 day SIM only contract is relatively easy (even with bad credit) and after you have started paying your monthly bills in full and on time you have already started to demonstrate that you are able to manage your financial obligations. This is essentially what credit rating are used for. They are used by companies as an indicator as to how well an individual manages their money. If payments are missed, there is the assumption that they will be missed in the future so companies are less likely to offer finance or phone contracts on that basis. The more you can demonstrate a responsible financial pattern, the better your credit file will look.

The benefit with using a SIM only contract to help your credit rating is that contracts can be taken out for just £5 per month so this represents one of the cheapest ways to take on a regular monthly financial obligation with a company that uses credit checks and credit files. There aren’t any other domestic services that you can get for as low a price as £5 per month that will provide as much benefit to your credit file to my knowledge.

The additional bonus is that once you have been successfully paying for your SIM only contract for a few months and as a consequence your credit rating has improved, it will also significantly improve your chances of getting a better SIM contract or mobile phone deal with a free phone included (particularly if you apply to the same network as your SIM only).

Yes. This is a simple (and free) trick that can help your chances of being accepted for any type of mobile phone contract. Being listed on the electoral roll signifies that you live at a fixed address which is an extremely important piece of information because the network or provider would know where to find you if you were to stop paying your bills. Without being listed on the electoral roll it will be difficult to get a phone contract regardless of whether your credit history is good or bad.

Currently there are only two networks that offer unlimited Internet SIM only contracts and they are T-Mobile through their Full Monty deal and the Three network through their One Plan deal.

Some providers have SIM contracts that offer data transfer at 4G speeds. EE currently has the largest coverage for 4G in the country but O2 and Vodafone are rolling out 4G SIM only deals and the Three network has a service that is currently in between 3G and 4G speeds although the fact that they offer truly unlimited data transfer is a big bonus for people that use their phones to stream over the Internet for instance.

Tethering is the ability to connect a WiFi/bluetooth enabled device to your phone in order to use the mobile data allowance supplied by the phones SIM card on other multiple devices. These could include PC’s, laptops, tablets, other phones, games consoles, etc. This means you can make multiple gadgets online devices by “tethering” them to your phone. The problem is that many networks either do not allow tethering full stop or they charge extra for you to tether your phone to a device.

The good news is that there is one SIM only contract that allows unlimited free tethering and that is The One Plan from Three.

Some tablets include the technology to accept SIM cards so that if a WiFi signal is not available, then the tablet can get online by using mobile data via a 3G or 4G signal. There are a wide variety of tablet SIM only contracts which cover all the main types of tablet such as iPad, iPad Mini, iPad Air, various Samsung Galaxy Tabs, Google Nexus, etc.

The main considerations when deciding on a tablet SIM are coverage, whether you require 3G or the faster 4G signal and the amount of data transfer included in the deal because free minutes and texts are not applicable to tablet SIM deals.

Yes you can keep your old number if you are taking out a new SIM only contract – even if you are changing to a completely new mobile network! To retain your old number you would need to contact your current mobile network and ask them for your PAC (Port Authorisation Code) number. They are obliged to give you this number even if you state that you are leaving their network. Once you have the PAC you should give it to the new provider and they will use it to transfer your mobile number onto your new SIM contract. Please remember that the PAC needs to be used within 30 days of it being issued.

SIM stands for Subscriber Identity Module – it is a smart chip similar to those used on credit and debit cards embedded in a standard sized plastic carrier – it is programmed with your phone number and other information that allows your network to securely identify you in connection with the handset that you are using. While the formats of the SIM card have reduced in size to aid the design of more compact devices, they have changed little since they first appeared in 1991. The original (full size) SIM card was the size of a credit or debit card and in fact this is how they still arrive from your network provider. You snap out the correct portion to suit the device that you are using.

There are currently 4 sizes of SIM available, although Full Size SIM cards are no longer in widespread use aside from as a carrier for the smaller formats – the one that you will need to use will depend on the handset that you have. If you are unsure, it should be listed in the specifications for your device. If you are replacing an existing SIM card, simply remove the existing one and compare it to the pictures of Standard, Nano and Micro SIM cards at the top of this page.

In some cases, adapters can be used to allow smaller SIM formats to be used in devices requiring larger format SIM cards.

Handsets are not specific to a particular user, and swapping your SIM into another compatible handset will result in your number moving to the new handset along with the SIM card.

Without a SIM card installed, a handset cannot be used to make calls. It is theoretically possible to make emergency calls from a handset with no SIM card installed, although this has been blocked in the UK due to the high percentage of hoax calls made from SIM-free handsets.

SIM cards are able to store contact information and text messages, however most modern handsets and smartphones use internal or external memory to do this, since the amount of data that can be stored on a SIM is strictly limited, and they were only designed to store name and phone number data. As most people have email and address data tied to contacts in their devices, SIM cards are not a viable option for contact or message storage on anything but the most fundamentally basic devices.