One possible reason is that if you purchased your shares after they went 'Ex dividend' you are not entitled to the dividend. The same is true if you sold your shares before they went 'Ex dividend'.

If your dividend is paid by cheque, another reason may be that you have moved and have not informed the Registrar, Equiniti, of your new address. If so, you should write to Equiniti to inform them that you have not received the dividend cheque.

If your dividend is paid directly in to your bank/building society account, another reason is that you may have changed your account. In this case, the payment to your old account will have been rejected by the receiving bank/building society. If this happens Equiniti will send a dividend cheque to you.

The contact details for Equiniti can be found here.

If you are a shareholder who has a UK bank/building society account, you can arrange through the Equiniti Shareview site to have dividends paid direct via a bank/building society mandate. Just click here to access the Shareview site.

You will need to contact Equiniti who will issue a replacement cheque/tax voucher. Equiniti may charge an administration fee for providing a replacement cheque/tax voucher.

The contact details for Equiniti can be found here.

You can arrange to have dividends paid direct into your bank or building society account which is a more convenient and secure method of payment than receiving a cheque. For details of how to do this please see the question 'Can dividends be paid direct to my bank/building society account?'