Unlike mobile phone contracts where you pay a set monthly fee in return for an agreed amount of free minutes and texts, pay-as-you-go (otherwise known as prepaid) plans offer the versatility to simply pay for the exact amount of talk time that you use. While mobile contracts give you an amount of free minutes depending on which deal you sign up for, many providers don't let you carry those minutes over to the next month if you don't use them, so in fact you lose out. Prepaid phones offer full control over the minutes you use and remove the responsibility of a binding monthly fee and contract. You simply pay for a phone, buy the credit from the service provider as you need it, and away you go.

Pay as you go phones don't even require you to register your name - only the mobile number is needed for your account. With most providers, you will need to top up your account every 90 days to keep the account active, but you have full say over the amounts you use. You will however need to buy a phone from the same provider as you get your talk time from.

Prepaid phones are most popular with teenagers who don't have credit cards and don't want the risk of not being able to pay monthly fees, with adults who only use their mobiles minimally and therefore can't justify the cost of a standard contract and with senior citizens who enjoy the simplicity.

Most pay as you go mobiles don't come with the advanced frills of smartphones - they focus on the core function of talking. Prepaid deals do vary according to the provider, so it's important to do your research to find the product that suits you best.

The following information gives you the features to look out for in pay as you go phones so you can make the most informed choice.

Style

Many people base their mobile phone choice on aesthetics, as in colour, size and design. As with other mobiles, pay as you go phones come in three main styles - slider, flip-top and candy bar. Size-wise, most prepaid phones are similar, being not too large to fit in your pocket. While it's important to find a mobile that you like the look of, don't forget to balance that with key features.

Phonebook

This feature determines how many contacts you are able to store in your phone. Contact capacities can vary depending on the brand and model, but most pay as you go mobiles come with at least a 200 contact limit, which should be enough for most people's needs.

Vibrating Alert

This feature comes in handy when you want to be alerted to a call without making an intrusive ringing sound, such as when in the library or cinema. The phone will merely vibrate to let you know when the call is received. You can also choose to have both a ring tone and vibration for times when you might not hear the sound, such as on busy high streets.

Speakerphone

This is a useful feature when multitasking - speakerphone allows you to talk and move about getting other things done at the same time, without having to awkwardly grip the phone between your neck and shoulder.

Battery Life

Pay as you go phones have a battery life measured in two ways - standby time which means your mobile is idle, and talk time when you make and receive calls. The general rule of thumb for adequate battery life is to choose a prepaid phone that will last a minimum of three hours without needing a recharge. This should be sufficient for most days.

Interruptions

Interruptions are inevitable when on a call. Choose a prepaid phone with features to tackle this. Call holding will put the person you're speaking with on hold while you deal with a knock at the door etc. Call waiting lets you put the person you're talking to on hold so you can take a second incoming call and then return to the original one. Conference allows you to talk to multiple people on your mobile at the same time.

All in all, pay as you go phones give you the added freedom of being able to talk on the move but without being tied to a fixed contract which you cannot cancel until the agreed term is met. There is now a wealth of different packages on the marketplace offered by providers, so it's important to shop around to make sure you're getting the best deal possible.