Give your old Kindle to Amazon to get an even bigger discount on the latest model

still rules the roost when it comes to e-readers, with its Kindle line up proving ever-popular for people who want to carry around their entire library on a portable device.

If you currently have an ageing Kindle and want to upgrade to something new, now could be the time. Amazon is currently discounting its most popular Kindle, the , from £159.99 down to £129.99, and will also give you a further 20 percent off when you trade in your current one.

That means you can for one of the best Kindles ever made.

I've tested and it is a great e-reader. It has a larger screen than previous generations at 7-inches while Amazon claims it's the fastest Kindle ever in terms of page turn speed, which feels true on use.

The battery lasts for more than a month if you don't have the frontlight cranked up to 100 percent, and the Kindle Store is easy to navigate when connected to Wi-Fi with an almost endless selection of titles to choose from, often at discounted prices.

If you want to pick up the newest Paperwhite at a hefty discount, head to the listing page on Amazon and click where it says 'Save 20% with Trade-In'. Here, if you're signed into the same Amazon account your current Kindle is registered to, it should appear in a list to click on. If not, search for the correct model in the search bar.

Go through the steps and Amazon will provide you with a label to print. Send your Kindle off to Amazon, and within three working days of receipt the firm will upload a 20 percent off voucher to your account to apply to the Kindle Paperwhite. Depending on the model, you'll also receive a gift voucher on your account to spend on anything you like.

It's worth noting the discounted Paperwhite here is not the Signature Edition, so you don't get the automatic light sensor or wireless charging, and this model is 16GB not 32GB. It's also the Paperwhite with ads, so you'll have to be OK with seeing ads for books and services on the lock screen.

Amazon lists this £129.99 deal as a 'Limited time deal' so it's not clear how long the discount will apply for. If you want to get the 20 percent off on this special price, it's best to act now. But also if you don't want to risk the price going back up, or you don't have a Kindle to trade in, this is still a good price for the product.

Amazon price comparison site Camelcamelcamel shows the cheapest the Paperwhite has ever sold for is £124.99, so this price is only £5 more, or even less when you trade in any Kindle.