Overview (F010.4)	Ancillary service endorsements are used by mailers to request an addressee’s new address and to provide the USPS with instructions on how to handle undeliverable-as-addressed pieces. The endorsements consist of one keyword: “Address,” “Return,” “Change,” or “Forwarding,” followed by the two words “Service Requested.” The endorsements are the same for all classes of mail, but the treatment and cost differ by class of mail. Use of an ancillary service endorsement on a mailpiece obligates the mailer to pay any applicable charges for forwarding, return, and separate address notification charges.
General (M012.4)	Proper placement of the endorsement is required. If the endorsement cannot be seen or understood, you might not receive the service requested. A return address as presented in A010 must be used and placed in the upper left corner of the address side of the mailpiece or the upper left corner of the addressing area. If a return address is a multiple delivery address, it must show a unit designation (e.g., apartment number). The endorsement and return address must read in the same direction as the delivery address.
Invalid Endorsement (F030.1.2)	Any obsolete ancillary service endorsement or similar sender endorsement not shown in F010 is considered invalid. Material bearing invalid or conflicting ancillary service endorsements will not be accepted for mailing. If discovered in the mailstream, pieces bearing an invalid ancillary service endorsement or conflicting endorsements are treated as unendorsed mail. Exception: Undeliverable Parcel Post, Media Mail, and Library Mail pieces that bear invalid or conflicting ancillary service endorsements are treated as if endorsed “Forwarding Service Requested.”
Other Physical Standards (M012.4)	An endorsement must be printed in no smaller than 8-point type, and it must stand out clearly against its background. Brilliant-colored envelopes and reverse printing are not permitted. There must be a 1/4-inch clear space around all sides of the endorsement.
	The endorsement must be placed in one of these four positions: Directly below the return address. Directly above the delivery address area (which includes an address block barcode and any related nonaddress elements such as a keyline or optional endorsement line). Directly to the left of the postage area and below any rate marking. Directly below the postage area and below any rate marking. This guide is an overview only. For the specific Domestic Mail Manual (DMM) standards applicable to this category of mail, consult the DMM sections referenced above and the general sections within each DMM module.

1. For Address Change Service with First-Class Mail and Priority Mail, see F010.5.1 for additional options.
2. Weighted fee (R600) is the appropriate single-piece First-Class or Priority Mail rate for the piece plus the nonmachinable surcharge if it applies (E130), multiplied by 2.472 and rounded up to the next whole cent.
3. For First-Class Mail and Priority Mail, Change Service Requested is only available with electronic Address Change Service (ACS). Only available for Priority Mail pieces containing perishable matter that bear the endorsement “Perishable.” Delivery Confirmation and Signature Confirmation are the only two special services permitted with this endorsement.