When your gadgets become unused and unwanted then it makes sense to sell them on - not only does it give you more cash to buy their replacements with, it also means someone else can use the hardware rather than having it all despatched to an e-waste site.
It sounds great in theory but there are dangers to look out for: when it comes to expensive electrical goods, plenty of people will be only too happy to rip you off or dupe you into a bad deal. With these tips and a little bit of common sense you can make sure you stay safe.
Stick to well-known sites
First and foremost you should stick to sites that are well-known and properly policed: your mobile operator's recycling service, eBay, CeX and Gumtree are some of the main ones. If you deal with companies rather than individuals (eBay and Gumtree) then you minimise some of the risk, but you're also likely to get a lower price at the end of the process.
Whatever site or service you decide to start dealing with, read through the official terms and conditions carefully, and make sure you're completely honest when it comes to describing the condition of your gadget and the accessories bundled with it - you're only going to get into trouble if you start trying to trick the people you're dealing with.
Keep records of all email exchanges, cash offers and so on, and take photographs of devices you're selling from every angle - that includes serial numbers and any damage you know about (this can help prevent disputes later on). It's also a good idea to note down the dates of each stage of the transaction, from posting off the item to receiving payment.
As documenting the process is so important, you should stick to the official channels when doing business with your buyer: if someone offers to settle a deal outside of eBay, for example, tell them thanks but no thanks. If you're selling on Gumtree, use the official messaging service rather than email so that copies are always kept of the conversation.
Wait for payment
It may sound obvious, but under no circumstances should you post anything off or meet in person until you've received the payment in full. If you're using a secure money transaction service like PayPal, you might want to leave a day or two for the payment to clear - be wary of anyone who's trying to rush through a deal without going through the proper checks.
Meeting in person is the best way to close a deal if you're selling to an individual, but take someone with you and meet on neutral ground. For cash transactions, make sure the banknotes you're given are genuine and don't be afraid to double-check the wad of cash you've been given (especially if we're talking about several hundred pounds).
Watch for warning signs
There are a few typical warning signs to look out for, though they don't always mean someone is dodgy in every case: wanting to send private messages outside of the exchange site you're working through, for example, or a reluctance to reveal any personal details (which would help you trace the buyer again if there was a problem later on).
It's usually anything out of the ordinary you need to look out for: if someone wants you to post something abroad perhaps, or needs you to send an item to a 'relative' instead. You should ask for a very good reason before you do anything that isn't normal procedure - again, check through the safety information for the website you're dealing with.
Do your research and wipe your device
eBay offers a comprehensive feedback system so you should definitely take advantage of this (and any other resources available to you) when it comes to learning about the people you're potentially dealing with - the auction site actually lets you block bids from buyers with a bad feedback score or who have been reported for not paying for items in the past.
Finally, make sure you're not leaving any personal information on your device - run through the reset process for whatever it is you're selling (having backed up everything you need to first). If you need help on how to do this, you should find some pointers on the manufacturer's website: here's Apple's advice for completely wiping iOS devices.