IHTM25123 - Valuing Businesses and Partnerships: Partnerships and lifetime transfers
If there have been lifetime transfers (IHTM14000) they should come to light when you have the replies to your initial enquiries.
Transfers of opening capital and changes in profit sharing ratios can lead to claims. If the deceased granted an agricultural tenancy to a partnership of which he was a member, this may lead to a loss to his estate unless the tenancy was granted for full consideration. But following the introduction of the Agricultural Tenancies Act 1995 (IHTM24240) tenancies granted on or after 1 September 1995 will not generally reduce the value of the estate, and that for events on or after 10 March 1992 agricultural relief at 100% will normally be available and take precedence over business relief.
Transfers of partnership capital will be potentially exempt transfers unless they were made before 18 March 1986. You will need to bear in mind the provisions at IHTA84/S113A (business relief) and IHTA84/S124A (agricultural relief).