You can renew a domain name at any point before it's expiry date. A domain name can be registered for up to 10 years in advance, which means it can be renewed for up to 9 years in advance.
Whether or not you want to keep your domain registered for years in advance is completely up to you. Any domain can be renewed at any time, so you can always just keep your domain name for the year. However some people like to keep their domains registered for long periods in advance to keep them safe.
If you have a domain name registered with us, with auto-renewal turned on and the payment method set to Credit/Debit Card, we will take payment automatically for your domain's renewal 3 days before the due date of the invoice we raise for it. If you have any questions about this, please don't hesitate to get in touch with us at firstname.lastname@example.org