The name of the regular instalment payments by investors, required to meet the annual costs for forest management and other services. The term also covers other contributions investors must make for the development and management of the investment which are prudent or necessary.

The largest amount of funding is required in Year One in order to buy the land and establish the treecrop. Lesser amounts are required from Year 2 through to about Year 9 to complete the pruning and thinning operations, to repay any initial mortgage borrowings and to pay the annual charges such as rates, insurance, maintenance and management. From about Year 10, only one Call is required to cover the ongoing annual charges.