Underlying profit before tax16,00214,308
Separately disclosed items within administrative expenses
IFRS2 share based payment charge22(1,687)(741)
Intangible amortisation12(974)(551)
Net acquisition costs30(264)(750)
Costs on exercise of executive share options(511)
Release of closure provision for TR Formac (Suzhou) Co. Ltd94
Profit before tax 13,07711,849

There were no separately disclosed items in 2016 (2015: £nil) other than the amounts detailed above.

During the period the IFRS2 charge increased significantly reflecting another year of the Deferred Equity Bonus scheme and also the acceleration of the 2014, 2015 and 2016 charges of this scheme for Jim Barker and Thomas Tan (TR Asia Managing Director, retired 31 December 2015) due to their Good Leaver status on retirement. £0.76m relates to the Deferred Equity Bonus charge for Executives who will continue in office and £0.83m represents the IFRS2 charge on deferred equity bonuses awarded to Jim Barker and Thomas Tan. The remaining £0.10m relates to the SAYE scheme.

The increase in the intangible amortisation charge has arisen primarily due to the purchase of customer relationships and an order backlog on the acquisition of Kuhlmann.

The total acquisition costs in relation to Kuhlmann amounted to £0.26m.