Kindle Unlimited is a monthly subscription service from Amazon and the Kindle ... you're reminded to return one of the e-books on your device. You'll never pay extra for a Kindle Unlimited e-book, but ...

For the monthly subscription price of £9.49 ... Essentially, when you subscribe to Kindle Unlimited, you pay £9.49 a month to have access to millions of free books from Kindle's library.

You'll need to add some card details but Amazon will only charge the £9.49 monthly amount after the promotional period ends. If you decide Kindle Unlimited just isn't worth it for you ...