They last for a month and then you top up online. They don't send you a text, but you can keep an eye online on how long you have left. You can also set it so your goodybag reoccurs every month. All 4 of my kids are on giffgaff and it works perfectly. The eldest does the £10 on and the younger kids get the £7.50 one.
Ive had a look on their forums, but I'm still confused. They have goodybags that seem good, but i cant see anywhere that tells me how long they last. Are they just for a month, and i then have to top up like I would if it was a payg? or do they last until they finish? Do they send me a reminder telling me I am almost at the end of my minutes etc? Any advice would be appreciated. I am a complete novice at this, as have had a two year contract for the last seven years and never had to worry about this before. But I'm trying to save some pennies now, and worried that I might end up spending more. tia