This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
If the alteration is material, the question next presented is whether it is presumed to be fraudulent or not. A material alteration, not clearly beneficial to the obligor, is prima facie fraudulent.1 An alteration increasing the rights of the obligee and the liabilities of the obligor, as increasing the amount of a note,2 is prima facie fraudulent. If on the other hand the alteration reduces the rights of the obligee or the liabilities of the obligor, as reducing the rate of interest3 or erasing the name of a surety,4 it is prima facie not fraudulent. A change in the date of payment of a note has been held to be not fraudulent prima facie.5