The SO system is designed for customers who collect magazines/series etc. and don't want the hassle of writing for each new issue whenever one is due. The forms you will receive are designed to let you specify which magazines/series you require and they will then automatically be sent on publication until your credit runs out. To keep the SO alive, simply send a further payment before your credit reaches zero (we will remind you when your credit runs low). Credit Card payment is handled slightly differently. No additional charges for SOs. Everything is explained in detail within the forms we will send you in response to your request for SO information.