It's nice to have you as a member of the Community, @jonathan-haslam.
Currently, paying for your QuickBooks subscription in advance isn't an option. The billing frequency for QuickBooks Online UK subscription is only monthly.
I can see how this feature would be beneficial to you and your business. I'll take note of your suggestion, so our developers have an idea of what they need to consider in future product updates.
As always, you can check regularly for product updates and feature enhancement through this link: QuickBooks Blog.
In case you want to read related articles in the future, visit our QuickBooks Community help website for reference: QBO Self-help.
Please know that you've got me here in the Community if you have any other questions with QuickBooks. Have a good one!
Thank you. That's a shame, but I've realised I can pay by direct debit, so have done that instead.