I think it's the same in all the EU.
Obviously if you don't charge VAT then you're not concerned by this.
Otherwise you only give an invoice when you have supplied the service and not before knowing if the customer want's to renew or not unless, of course, if you have a contract with them that specifies the account is automaticaly renewed if they don't warn you however many days/weeks before their hosting expires.
Good news about the proforma invoicing, however I don't think we will be able to wait so we will continue with our projet of developping our own system.
There are some things like queues (for suppliers that limit the number of simultanious connections to their API) that we would have to develop our own modules for anyway.