You must include the establishment number Est#B on the final product label.
If the label qualifies for generic approval, meaning it doesn’t include special claims or require LPDS (Labeling and Program Delivery Staff) stamping, you simply need to update the establishment number on the label and list Est#B on the Application for Label Approval.
However, if the label includes a claim and has already been stamped and approved by LPDS for another sister establishment, you’re allowed to use a copy of that approved label. In this case, you still need to ensure Est#B appears on the final label applied at the sister facility. This process is referred to as a “blanket” label approval, and it’s described in the FSIS Compliance Guideline for Label Approval.
As for including two establishment numbers, that scenario I have only seen in the following scenarios. Scenario#1, if Est#A ships a case containing ten ground beef logs to Est#B, and Est#B repackages only two logs, the logs may retain Est#A on their individual labels. Est#B must then appear on the shipping container or outer box. This labeling approach follows FSIS Directive 7220.1 and is outlined in Policy Memo 090 & 090B.
Scenario#2: When a product is not intended for retail sale and thus wholesale, the use of multiple establishment numbers is allowed. While this practice is not common and I wouldn't not recommended, it is allowed under current guidance. You can find further clarification online if you search askFSIS Public Q&A: Multiple Legends
Research the documents mentioned for further clarification.
Edited by FSQA-USDA, Yesterday, 09:27 PM.