These proposed regulations set out various rules related to claims for refund or credit for amounts required to be withheld under chapter 3 or 4 of the Internal Revenue Code.  In part, these regulations limit claims for credits or refunds related to amounts withheld under chapter 3 or 4 to the extent that the relevant withholding agent failed to deposit an amount required to be withheld and deposited. These regulations also modify procedures related to amending Forms 1042-S (Foreign Person's U.S. Source Income Subject to Withholding). These regulations further modify rules related to refund or credit claims when a withholding agent pays the required withholding on behalf of the beneficial owner. In addition, these regulations make other modifications and clarifications with respect to claims for credit or refund based on withholding required under chapter 3 or 4.