The £20 annual discount is available to new customers and for the first year only, after which the price goes back to £79 per year. You can still sign up for the 30-day free trial too.
The online shopping giant is concurrently running another promotion that gets you a £10 credit to spend on Prime Day (or until 28 July if you want to wait) when you install the Amazon Assistant browser plug-in. You'll have to add it via Amazon's dedicated page though and not through your browser's plug-in store – here's how.
For everything there is to know about Amazon and all the promotions it's running now, see our dedicated article that rounds up the best Amazon deals along with top tips on saving.
Keep in mind, it's a good time to save over all with other retailers competing with Amazon. We're keeping tabs on all the major sales in the UK right now beyond Prime Day in a handy list here which we're continuously updating.
You can browse through some of the top Amazon deals on now below:
Amazon Echo Dot (3rd-gen)
Now: £39.99 (£10 off with 2 free months of Amazon Music Unlimited)
Amazon Echo (3rd-gen)
From: Currys PC World
Now: £49.99 (£40 off with 6 months of Spotify Premium)