Post office wills are notorious amongst estate practitioners for being rife with issues. They do not provide for all different possible circumstances.
Without receiving advice from an experienced estate planning practitioner, you are likely to miss key factors regarding your circumstances that require specific considerations and plans put in place and recorded correctly in your will.
A very common requirement often overlooked is the requirement for testamentary trusts, which provide many benefits to your prospective beneficiaries, including asset protection, tax benefits, and risk mitigation.