A certificate is money you leave with a bank for a fixed time, such as one or three years, in return for a yield the bank states up front. With a fixed certificate the yield stays the same for the whole term, even if interest rates in the market change.

Fixed and variable yields

With a fixed certificate you know on day one what you will get. With a variable one the yield follows the Central Bank's decisions, rising when it raises interest rates and falling when it cuts them.

When the return is paid

• Monthly: a small part arrives every month, which suits anyone who needs a steady income.
• Quarterly or yearly: about the same amount, in fewer payments.
• At the end of the term: the whole return arrives at once, often at a slightly higher rate.

How to work out what you get

Multiply the amount by the yearly rate to get one year's return. For example, 100,000 pounds at 22% a year gives 22,000 pounds a year, or about 1,833 pounds a month.

Before you buy

Ask about the early withdrawal penalty, because most banks keep part of the return if you take the money out before the term ends. Compare the yield with treasury bills and investment funds on the savings pages.

This guide explains how things work and is not financial advice. Check the current numbers in Geneh before you decide.