If you’ve come to the end of your contract or are looking to sell your phone along then you’ll need to unlock it. If the handset’s SIM-only, this won’t be necessary, as the phone will not be locked to a network.

However, if you had your phone on contract from a network or carrier, if you’re in the US of A, then you will need to unlock it before selling it on or switching networks to a cheaper, rolling monthly plan.

Why Do Networks Lock Phones?

This is a good question. The simple answer is that a phone on contract is like a leased car: you don’t really own it. At least, not until the contract is up and you have covered the purchase cost of the phone (and then some) with your monthly payments.

Once you have done this, you own the phone. If you’ve kept it in good nick and want to sell it along the only way to do this is to unlock the phone from the network or carrier.

Even if you’re giving the phone to a friend or relative, you should still unlock it – unless they're on the same network as you. Then you can leave it alone, as it will function with a SIM card from the came network or carrier.

How To Unlock A Phone

There are multiple ways. The most common – or, the one I’ve always used – is going to one of those shops, the one’s usually built in between two normal shops on Oxford Street, and getting it done there.

For the most part this is fine. But what if you wanted to do it online, while at work, or without leaving the house? Simple: you do what I just did for my mum’s old phone – you go online and do it via DoctorSIM.

DoctorSIM is quick, easy and priced competitively. How it works simple: you select which phone you want to unlock, complete the request form, and then you receive an unlock code – it’s that simple.

Once you have the code, simply type it into the desired handset to unlock it.

To unlock my mum’s iPhone SE it cost me £44.95 and the code came through after three days. DoctorSIM says it can take up to 10 days to deliver the code, though, so if your’s doesn't come as fast do not worry – it’s on its way.

Prices vary depending on what phone you’re looking to unlock. A Samsung from on Three, for instance, is only £22.95 with an average delivery time of 16 hours. Why is this? The most likely reason is that Apple iPhones are harder to deal with when accessing unlock codes.

Either way, if you’re looking for a decent online service for unlocking your phone I would 100% recommend you check out DoctorSIM. I was very impressed by the service and would use them again in a heartbeat.