I've used ATT prepaid 45$ plan while visiting US for couple of times now. If i'm not mistaken, to keep that number alive, once in 3 months a refill is required. I did some googling and found a 100$ refill card which should keep the number alive for 1 year. How's data handled when this 100$ refill card is used? How much data (per month) i could use?
A $100 refill is simply a $100 on your account. Whatever data you have depends on your plan. If you put a $100 into your account and keep the $45 plan, that $100 will just pay for your plan for two months. You still only get whatever data comes with the $45 plan. If you run out of data during the month, that plan allows you to buy extra data, $10 for 1GB or $20 for 3GB.
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