How much are your certificates worth?

For an accurate valuation

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Get an estimated valuation

The calculator gives a quick estimated value for your Index-linked Savings Certificates. The estimate is:

  • for guide purposes only
  • based on the Retail Prices Index (RPI) figure and Consumer Prices Index (CPI) figure last updated on April 2024
  • only relevant if you cash in your Certificate in May 2024
  • only for Certificates within their current term

Do you have a Certificate due to mature this month?

If so, this calculator may not be able to give you a result as its too close to maturity. Please see the maturity letter we sent you, which gives you a valuation of your Certificate.

To check the RPI, visit the Office for National Statistics website at and search for RPI All Items Index or CPI All Items Index.

Using the calculator

Have the following to hand:

  • Amount - The amount invested at the start of the current term
  • Investment term - your investment has a term of 2, 3 or 5 years
  • Day, month and year of investment - The date the current term started

What’s meant by 'current term'?

If your Certificate has been renewed, the current term started on the renewal date. For example, if you originally invested in a 5-year Certificate 20 July 2018, you should enter the renewal date of 20 July 2023.

You’ll also need to enter the value of your investment on that date. You can find this on your latest investment record.

Cashing in penalty

If you cash in before the end of the term, a penalty will be deducted from your payment and you won't earn any index-linking on the whole Certificate for the investment year in which you cash in, even if you only cash in part of it. The penalty and loss of index-linking are not included in the estimate given by the calculator.