I think the payment of windfall shares was made to all those members who had a "qualifying" policy, which meant a "With Profits" policy. Your pension policy may, or may not be a "with profits" and the only way you can find out is to write to Standard Life giving them all the details. If you haven't received shares and do have a With Profits policy, is it possible that you have moved house or changed your address since taking out the policy 15 years ago, in which case they may have written to a former address and had the documents returned as non-deliverable.