How are the premiums for a whole of life plan treated for IHT purposes, where the policy is held in trust?

These would normally be covered by one of the IHT exemptions such as:

• the annual £3,000 allowance; 
• normal expenditure out of income exemption - the definition of income for this purpose doesn't include withdrawals from investment bonds, payments from a discounted gift trust or payments of the exempt capital content from an Aegon Secure Lifetime Income product; and  
• payments not covered by an exemption will be classed as a gift for IHT purposes - these could be chargeable lifetime transfers (CLTs) or potentially exempt transfers (PET) depending on the type of trust used.