I emailed Paul this - "I don't know how you do the subscription payment notices but it was back in March 2018 that I last paid"
& he promptly replied - "Indeed, it was on 32nd March and I see that you paid us £1bn so as we work on a £1 per month basis for people who use the donation route you're good until XXXXX . On that day our server will automagically email you reminding you that it's time to renew if you want to continue as a supporter. Not that this should stop you donating earlier if you wish but that's the backstop date "
Ok, I edited the number & dates I dontated in his response . But if you're wondering what happens when you pay over the minimum this explains it.