Many Nationwide members could be up to £759 better off down the line just by moving some money into a new account – and leaving it there. The world’s biggest building society has this week let its many customers know of an exclusive deal they may want to take up.

In an email to members, Nationwide said: “We want to help you get more out of your savings with us.” It further explained that its new Member Exclusive Bond account offers a savings rate of 5% fixed for 18 months.

You can deposit anything from £1 to £10,000. If you were to put in the larger amount, this would amount to £759.30 in interest at the end of the fixed term (18 months).

In order to open the account, you’ll need to be an existing Nationwide member, and aged 16 or over. You can’t have more than £10,000 in the account, and you’ll need to be registered to use the internet bank and have a valid email address.

Once the account has been opened, you’ll have 14 days to pay money into it. From day 15 you can’t make any more payments, and if you’ve not deposited anything the account will be closed.

And if you change your mind you have until day 14 to close the account. After this, Nationwide says, “you can’t normally take any money out of your account or close it before the end of the fixed term”.

Interest is paid on the anniversary of the account being opened, at the end of the term, and when the account is closed. Nationwide further explains: “If you open your account on 29 February, we’ll pay your interest on 28 February.”