It will depend on the gas station and the owner/manager on how it is set, but this is done in the US. In my experience, a credit card of one type (say the franchise credit card) will be set to a limit of $300, while another one (say a VISA) might be set to $100. A debit card is limited to about $40 or $50. To the consumer, unless they hit the limit on the debit card, there is no limit. The only time I ever saw a guy hit the credit card limit was when he was filling up a truck and about three large gasoline drums (he worked for a motorcycle sales company and that was how they had gas for test drives, giving a full tank to buyers, and the like, as they didn’t have their own small underground tank.) I don’t know how sophisticated the system is or whether or not it one could theoretically set itself to the max limit of the credit line.
I accidentally stole a tank of gas from a station in central Ohio a few years ago. I pumped, went in and got snacks, paid for the snacks, and drove off. I only remembered that I hadn’t paid when I turned the car back into Hertz. Whoops! No time to go back now, got a plane to catch. Normally, I’d pay at the pump, but I’d specifically wanted a soda. Then, when I got to the counter, I was distracted and paid with cash.
This is a risk that stations take when allowing patrons to pump without paying. The losses are part of doing business, easily documented, and tax deductible, so it isn’t that huge an issue. Pre-pay rules reduce the problem, but they create more work for the clerk, and more hassle for the customer, so they may have an overall negative effect on business. In fact, in areas where both types of stations exist, it’s my experience that the nicer, more prosperous stations allow pump-then-pay. It many be more worthwhile to require pre-pay when the customers are predominately transient, e.g. near freeway access points, as opposed to developing loyal customers in communities.
This seems like a good time to repeat the rule of thumb on stealing:
Never steal anything worth less that twice your annual salary.
Collorary for businesses: Never give an employee access to anything worth more than twice their annual salary.