Thanks Ruhul for replying so soon. I’m not yet familiar with how callback functions work, so although I’ve combed through the mm forms code, I can’t figure how to call the php function. Probably other people would also need to collect extra info before Simple Shopping Cart checkout too. I see now that empowerednutrition.com/shop/ mentioned above is just using your eShop plugin to collect a coupon code. Using mm forms would make that easily customised and store the results, but the plugin seems to be unsupported (unlike yours which is fantastic!). If you have any ideas that can get me going, I’d be very grateful. Kind regards, Joan.