Mezzanine Bonds

I had this question while reviewing mezzanine debt securities. The online textbook says that these bonds are often issued with different features like PIK. I understand PIK essentially means adding interest payments to the principal and paying all together to the investor at maturity.

My question is:

Will the interest payment always be based of the rate on par value or is there compound interest because of an increasing principal?

Good question!

It depends on the specifics on the bond, but generally yes - interest is calculated on the new total principal including the added PIK amount.