Is this a personal pension in your own name or is it a pension from previous or current employment?
If it is a personal pension you cannot access it until age 60. 25% of the value will be available as a cash sum with balance invested in an annuity or Approved Retirement Fund.
If it relates to current or previous employment (and you are not a member of any other company pension scheme) then you will be able to take some or all of it now in cash form (depends on size of fund, service with company and final salary). Any balance will be invested in an annuity.