It depends on the product you're renewing. For me it's monthly passes, so it goes through on a date late in the month; for the other user he has an automatic top-up set for when his balance dips below a certain value.
Upon further discussion on Twitter with the GRT team, it looks like mine was due to an unrelated credit-card issue, so my alarm may not have ben as urgent as I indicated.
Upon further discussion on Twitter with the GRT team, it looks like mine was due to an unrelated credit-card issue, so my alarm may not have ben as urgent as I indicated.