How we work out your round-ups
We calculate your round-ups based on the first amount charged to your account. This is called the 'auth' amount. For example, if you tap into the Tube and it charges you 10p but updates to £7.50 later on, we'll round-up from the 10p.
When you're paying in a foreign currency, your card transactions are converted to pounds by Mastercard before they appear on your account. We'll use this GBP amount to round-up.
A bit about interest
You get 5% AER (variable, 4.89% gross) interest, calculated every day and paid every month. AER stands for Annual Equivalent Rate, so you'd earn 5% over the whole year if you didn't move money out.
That means, if we rounded up £10 for you on your first day, you'd earn £0.50 in interest over the year. If you rounded up nothing else, you'd have £10.50 at the end of the year.