Rental not received

A friend asked me this question over the weeked.

She and her brother inherited a commercial property from their parents. Her brother has a company which runs from the premises and to keep things "fair" they have drawn up a lease agreement between themselves as joint owners and the company. The brother's company is not making enough money to pay the rent and family ties being what they are the sister has agreed to forfeit rental due for "the time being". Her question is, is she still liable for tax on income per the lease agreement? Personally I feel she cannot be liable as she is not in receipt but the lease may complicate this.

Any help most welcome!

Thanks

Mandy

Mandy Stephens