If you have Tesco Clubcard or Nectar* points to redeem against a Merlin Annual Pass you will receive a Standard Individual Pass. You can choose to upgrade to a Premium Pass when you exchange your voucher at an attraction or at any point during the lifetime of your Pass for £50 per pass.
*Please note: From 23rd March 2018 you will be unable to use your Nectar points to redeem a Merlin Annual Pass. All vouchers issued prior to this date will still remain valid and can be redeemed until 31/12/2018 - please check Opening Times prior to travelling to avoid disappointment.
We hope this answers your question.