Mr. Martin's current interest payment is 2.5% over a prime rate of 3.25%, which yields a 5.75% interest rate.

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Users of the ReservePlus loan card pay themselves an interest rate pegged at the prime rate (currently 5%) plus a service fee of from 2.9% to 3.25% of the outstanding balance, which goes to Bent's firm.

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The interest rate of the loan is generally a low rate of prime plus one percent.

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Still, the vast majority of loans are repaid, and you will pay yourself interest, often at the prime rate plus one percentage point, or 4.25%.

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The sub-prime lending market - worth billions of pounds - involves lending to people with poor credit records at an interest rate premium.

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Most of those are tied to the prime rate, so if the prime rate were to increase, then the interest rates on those credit cards will undergo a corresponding increase.

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And on the other, the exchange rate has been one of the prime reasons why British inflation has stayed so low since the committee was given control of interest rates in 1997.

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