If you've got Amazon Prime as a way to get your parcels delivered fast and for free, as a side effect you'll also have Twitch Prime. The service, which gives users a free monthly channel subscription as well as free games and in-game loot, has now partnered with Nintendo to give away up to a year of free access to the Switch's online features.
Here's the deal: if you currently have Twitch Prime, and are in the UK, you can click here, select to receive three free months of Switch online, sign into your Nintendo account, and bam, done. You can redeem these free three months no matter how recently you joined Twitch Prime, and you can redeem them even if you have a current paid subscription to Switch Online – they just stack on top.
Then, 60 days after you redeemed the first code, you can then go back to this page here, and click to redeem an additional nine months of free Switch Online, once again redeemable even if you already have an active paid subscription.
Now, there is one caveat: family accounts. If you, like me, have a Switch Online family account set up so your friends with a Switch can trade shiny Pokémon with you, you'll be out of luck. The code won't redeem, full stop. There's no option to redeem it for use after your family plan runs out; you're just out of luck. This is a single account only deal.
Still, if you've got a friend who wants a year of Switch Online, you could probably redeem it for them, if you're feeling generous.