You can purchase a pre-paid credit card and load it with ever how much you need. Later you can re-load that same card. Keep the amount of your standing order always loaded in your pre-paid card. No interest to pay, If in the future you want to add to your standing order, all you have to do is loaded the needed amount in your pre-paid credit card. If you always keep a balance on the card that is equal to your standing orders, there will never be a problem.
