These are set at the state level in the United States, and it can vary widely. A lot of the states will have upper limits for different kinds of lenders. For payday lenders, they may set it at 300%, 500%, 600%, or maybe even higher than that. For other kinds of lenders, they'll set it for a lower amount. In the United States it varies very widely.
Great Britain doesn't have an upper lending rate, or any kind of lending rate, as far as I understand.
Those are the ones we looked at.