Is a promissory note bonus taxable income?

It can be, but the answer depends on what the employee received. If an employer transfers a promissory note as compensation and the note has a fair market value, the employee may have wage income measured by that value. The tax result is not automatically the face amount of the note.

If the employee only has a restricted future payment right, the analysis may shift toward constructive receipt, economic benefit, or deferred compensation rules. For exam purposes, ask whether the employee has cash, property with measurable value, or only a future promise subject to meaningful restrictions.