If you're thinking about upgrading to a new iPhone now that the iPhone 6 and iPhone 6 Plus have arrived, you might want to consider trading in your old one. In this article, we're going to take a look at some of the options available for getting the most money for your iPhone, whether it's an iPhone 5S, iPhone 5C, iPhone 5, iPhone 4S, iPhone 4 or an even older iPhone. We'll also offer some advice on how to prepare your iPhone for sale. See also: Which iPhone should I buy?

How to sell your iPhone: Prepare your iPhone for sale

Before you sell your iPhone, you'll need to make sure that you've wiped all of the data you've got stored on it, to prevent the person who buys it getting access to your sensitive data and details.

It's a fairly simple process, which we explain in our how to wipe your iPhone or iPad article.

Don't be tempted to sell your iPhone with your data intact because it has Flappy Bird on it, or something similar. When the game was removed from the iOS App Store this year, users began selling their iPhones for slightly more cash on eBay by advertising the fact that Flappy Bird was installed. The problem is that the game is connected to your Apple account, and therefore you're selling them some of your personal data too.

You'll also want to gather together all of the cables, accessories and packaging you've got for the iPhone. Make sure you specify what the iPhone comes with in terms of cables and packaging, particularly if you're selling on eBay.

Read next: Best place to buy an iPhone 6 in the UK

How to sell your iPhone: How much can I get for my old iPhone?

How much you get for a second-hand iPhone depends on what model you've got and where you sell it. Typically you'll get more cash from a private sale than from a shop or services (as they need to include a mark-up when they sell it on). But it's less hassle to take it to somehwere like Computer Exchange or Cash Generators.

Indeed, you can buy and sell second-hand iPhones right here on the Macworld UK website. With our partner Mresell we run a service via which you can sell your unwanted Macs, iPhones and iPads. Once a price is agreed we either pick up your Mac, or you can take it to a certified Apple reseller after which payment is made. Either way, the iPhone is then thoroughly checked, refurbished and reconditioned, and listed for sale on the Buy/Sell section of this website.

Apple itself offers a fair deal through its iPhone trade-in programme, which could get you up to £220 to put towards a new iPhone.

The iPhone Reuse and Recycling Programme allows customers to trade-in their old iPhone – from the iPhone 3GS to the iPhone 5C and iPhone 5S – by visiting an Apple Retail Store with their old iPhone or visiting Apple's Reuse and Recycling webpage. Apple is no longer offering trade-ins of the original iPhone, as it has "no resale value" according to the company.

If you decide to take your old iPhone into an Apple Retail Store, Apple's staff will look over it and give a trade-in price estimate. This price is based on the condition of the hardware and the model of iPhone. Customers can then get that value subtracted from the price of a new iPhone or other Apple product should they decide to trade-in.

If you choose to go through the trade-in process online, you'll need to visit Apple's Reuse and Recycling webpage, answer a set of questions to help Apple come up with the estimated value of the device, then send your iPhone to Dataserv for evaluation. Once Dataserv (Apple's recycling partner) has checked your device and determined the accurate trade-in value, you'll get that money deposited into your bank account.

See also: iPhone buying advice

Find out how to unlock your iPhone 4 here.

You can get a reasonable amount of money from Apple, third-party buy-back companies in exchange for your old iPhone, particularly if you've kept that iPhone in good condition. You can also sell it on eBay, Gumtree or similar. Here, we talk you through the best places to get money for your iPhone, and let you know how much to expect to recieve.

How much is my iPhone worth? Original iPhone value

If you own the original iPhone, you probably won't be too pleased with Apple's valuation. Ahead of the iPhone 6 launch, we found that the maximum Dataserv estimate for the first iPhone is £5.00. Now, though, Apple says that the original iPhone has "no resale value."

You'll probably get something for your original iPhone by selling it on eBay. In fact, one Australian Ebay seller has been attempting to sell a brand new, sealed first generation iPhone for £55,513, which is a bit extreme. A more realistic expectation is £20, though if it's brand new or comes in the box you might find that it sells for £100 or more. Don't forget, though, that you'll need to pay eBay and PayPal fees on top of postage if you sell through the online auction site.

It's worth investigating Gumtree to avoid such charges, though you won't get the support you get from eBay and PayPal if you use that service.

How much is my iPhone 3G worth? iPhone 3G value

Similarly, those with an iPhone 3G will want to think about an alternative way of getting money from their old device. Apple offers says the iPhone 3G had no trade-in value through its Reuse and Recycling programme. Carphone Warehouse's trade-in offering is £2.70 for the iPhone 3G, but on eBay, you could get £20 to £30 for it.

How much is my iPhone 3GS worth? iPhone 3GS value

If your iPhone 3GS is in tiptop condition, you could get up to £10 for it through Apple's Reuse and Recycling Programme. That's still not as much as you could get from eBay, though. A 32GB iPhone 3GS could get you around £50 through the online auction site.

Carphone Warehouse offers just £8.10 for a 32GB iPhone 3GS.

How much is my iPhone 4 worth? iPhone 4 value

Onto the iPhone 4 now, and for a 32GB model in good condition, you're looking at a sum of £80 from Apple's Reuse and Recycling programme. That's much more than offerings from Carphone Warehouse (£45) and other third-party trade-in services from companies such as O2 (£75) and Envirofone (£70).

It's also not dissimilar to the kind of money you can expect to get for your iPhone 4 if you decide to sell it on eBay. Don't expect to get much more than £100 for a 32GB good condition iPhone 4 on eBay.

It's therefore worth checking out Cex if you want to sell your iPhone 4. It claims to offer up to £100 for a 32GB model.

How much is my iPhone 4S worth? iPhone 4S value

If you've got an iPhone 4s, the maximum amount that Apple will give you is £130. That's for a 64GB iPhone 4s that has no liquid damage, no display damage and no other damage.

If you've got some scratches on the iPhone, you're looking at a maximum of £97.50, and as soon as you add further damage you can expect an estimate of £60 or less.

The good news is that even a 16GB model of the iPhone 4S can get you £110 through the Reuse and Recycling programme.

Apple's offerings here are more generous than third-party services we checked, including Envirofone (£110 for a 64GB model) and Carphone Warehouse, which only offers £67.50 for a working 64GB iPhone 4S. Cex, on the other hand, offers up to £131 for the iPhone 4S.

We'd suggest thinking carefully about Apple's offer here. We've seen used iPhone 4S models go for just £100 on eBay, and not many appear to sell for much more than £150.

How much is my iPhone 5 worth? iPhone 5 value

Apple is offering up to £220 for a good condition iPhone 5 through its Reuse and Recycling Programme, which we think is rather generous, and either matches or beats many of the iPhone 5 models we've seen selling on eBay.

O2 offers £180 for a 64GB iPhone 5, while Envirofone offers £131 and Mazuma Mobile offers up to £160, so Apple beats those third-party trade-in services too.

If you're worried about scratches on the back of your iPhone 5, you might be looking at a price of £165 or less, though. However, even if you've got a 64GB iPhone 5 with a completely smashed display, Apple will still give you £143.

For a 16GB iPhone 5 in good condition, you're looking at a value of £190 from Apple, while a 32GB model is worth £210 to the company.

You'll be taking a risk if you try selling your iPhone 5 on eBay, as it looks like they go for around £200 each so Apple's offer is better.

How much is my iPhone 5s worth? iPhone 5s value

Here's the biggy: you can now trade-in your iPhone 5s with Apple. The company is offering up to £320 for the iPhone 5S.

That's more than most of the third-party buy-back companies and trade-in programmes we've tried. Carphone Warehouse offers up to £216, O2 offers £275, Envirofone offers up to £265 and Mazuma Mobile offers £260.

eBay is an appealing option, though, as you could get get more than more than £350 for a good condition 64GB iPhone 5S there.

How much is my iPhone 5c worth? iPhone 5c value

Similarly, Apple has just kicked off a trade-in for the iPhone 5c, offering up to £220 for a 32GB model. That's more than all of the third-party offers we've seen. Carphone Warehouse only offers £112.50, for example.

You can sell your iPhone 5c on eBay for £200 - £300 depending on the condition.

Read next: How to set up a new iPhone