This article, the final installment of the series on Wisconsin Municipal Indebtedness, which began in the March issue, is concerned with the effect of failure to comply with the constitutional and statutory requirements concerning municipal obligations. The first part of this article demonstrates how restrictive these rules, developed in an era when municipal obligations were much more speculative, are, especially with respect to the rights of creditors. In the second part of the article all three authors of the series collaborate in presenting recommendations which suggest means of modernizing the law of municipal indebtedness.