Ancillary Service Endorsements
How to tell the USPS what to do with your undeliverable mail — and get address corrections back.
What Are Ancillary Service Endorsements?
An ancillary service endorsement is a printed instruction on your mailpiece that tells the USPS how to handle it when it can't be delivered as addressed. Without an endorsement, the USPS follows default handling rules for each mail class — which may mean your piece is silently discarded with no notification.
Endorsements give you control. Depending on which one you choose, the USPS will forward the piece, return it to you, provide an electronic address correction, or some combination. Each endorsement has different costs and behaviors depending on the mail class.
The endorsement line must be printed in a specific location on the mailpiece — typically directly below the return address or directly above the delivery address block. Cornerstone prints the correct endorsement in the right position on every piece we produce.
The Five USPS Endorsement Types
Address Service Requested
The most commonly used endorsement for mailers who want to keep their lists accurate. It provides address correction information while still attempting to get the mailpiece to the recipient.
First-Class Mail Behavior
- → Mail is forwarded to the new address for 12 months
- → A separate address correction notice is sent to the mailer
- → After 12 months, the piece is returned with the reason for non-delivery
Marketing Mail (Bulk) Behavior
- → Mail is not forwarded
- → The piece is discarded
- → An address correction notice is sent to the mailer (fee applies)
Return Service Requested
Use this when you need the physical mailpiece back if it can't be delivered. The USPS will not forward the mail — it comes straight back to you with the reason for non-delivery attached.
First-Class Mail Behavior
- → Mail is not forwarded
- → The piece is returned to the sender with the new address (if available)
- → No additional fee for return of First-Class mail
Marketing Mail (Bulk) Behavior
- → Mail is not forwarded
- → The piece is returned to the sender (return postage charged)
- → New address provided on the returned piece if a forwarding order is on file
Change Service Requested
The most cost-effective option for large-volume mailers who want electronic address corrections without the expense of physical returns. The mail is not forwarded or returned — it's discarded. But you get the correction data electronically.
First-Class Mail Behavior
- → Mail is not forwarded
- → The piece is discarded
- → An electronic address correction (ACS) is sent to the mailer
Marketing Mail (Bulk) Behavior
- → Mail is not forwarded
- → The piece is discarded
- → An electronic address correction (ACS) is sent to the mailer
Forwarding Service Requested
This endorsement prioritizes getting the mail to the recipient at their new address. It's similar to the default First-Class behavior, but it applies the forwarding instruction explicitly to other mail classes as well.
How It Works
- → Mail is forwarded to the new address (if a forwarding order is on file)
- → No address correction is returned to the mailer
- → If no forwarding order exists, the piece is returned to the sender
Temp-Return Service Requested
A specialized endorsement used primarily for Periodicals. It requests temporary forwarding with a physical return after the forwarding period expires. This helps publishers manage subscriber address changes.
How It Works
- → Mail is forwarded during the temporary forwarding period (typically 60 days for Periodicals)
- → After the forwarding period, undeliverable pieces are returned to the sender
- → The returned piece includes the reason for non-delivery
Quick Comparison Table
| Endorsement | Forwarded? | Returned? | Correction Provided? |
|---|---|---|---|
| Address Service Requested | Yes (FC only) | After forwarding expires | Yes — separate notice |
| Return Service Requested | No | Yes — with reason | On the returned piece |
| Change Service Requested | No | No — discarded | Yes — electronic (ACS) |
| Forwarding Service Requested | Yes | If no forward on file | No |
| Temp-Return Service Requested | Yes (temp) | After forwarding expires | On the returned piece |
What Happens With No Endorsement?
If your mailpiece has no endorsement printed on it, the USPS follows the default handling rules for that mail class:
First-Class Mail: Forwarded for 12 months, then returned to sender. No separate correction notice is sent.
Marketing Mail: Not forwarded. Silently discarded. No notification to the mailer. This is the worst-case scenario for list accuracy.
Periodicals: Forwarded for 60 days. After that, an address correction notice is sent to the publisher.
Choosing the Right Endorsement
The right endorsement depends on your priorities:
Want the mail delivered AND corrections back? Use Address Service Requested.
Need the physical piece back? Use Return Service Requested.
Just want electronic corrections at the lowest cost? Use Change Service Requested.
Don't care about corrections — just deliver it? Use Forwarding Service Requested or no endorsement.
Cornerstone Handles Endorsements for You
We'll recommend the right endorsement for your mail class, volume, and goals — and print it correctly on every piece. Combined with our NCOA processing and CASS certification, your mailings achieve maximum deliverability with minimum waste.
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