I am not sure why the option is not available within the Expense Claims form. The Expense Claim is only an alternate form of a Purchase Invoice.
An Employee/Owner gives you an Expense Claim, a Supplier gives you a Purchase Invoice - both create a payable liability. If Manager didn’t have the Expenses Claim tab, then those Employee/Owner’s would just be another Supplier.
As the user has the flexibility of that exclusive/inclusive option within a Purchase Invoice, therefore it should also be available within the Expense Claim - an example being.
The Expense Claim Payer has gone to the supermarket and purchased 100.00 of items of which 20.00 (tea/coffee) are for the business and the rest is private. The supermarket provides a tax exclusive invoice so the business proportion is 20.00 plus taxes.
Currently, for the Expense Claim the user has to manually calculate the tax inclusive amount (20 + taxes) prior to the entry, whereas, if that same supermarket invoice was entered as a Purchase Invoice then the user could just enter 20.00 and select an appropriate tax code.