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Author's profile photo Braden McCollum

What is FSS?!?

What is FSS? The Flat Sequencing System (FSS) is the latest generation of mail-sortation equipment being deployed by the USPS®. The FSS will automatically sort flat-sized Periodicals, Standard, and Bound Printed Matter mailpieces into delivery point sequence at very high speeds. Each FSS machine is about the size of a football field once all components are set up and can process upwards of 300,000 flats per day. With FSS machines processing 16,500 flats per hour, the USPS will be able to remove thousands of hours of manual letter carrier delivery point sequencing (casing) of the mail. The USPS plans to deploy 100 FSS machines in Phase 1 at 47 locations around the country. As of November 2010, there are already 29 systems online and processing mail. For full details on everything in the USPS Flat Sequencing Strategy, go to the official USPS FSS Page on RIBBS: . From the ‘FSS Deployment Information’ link you will be able to see a complete listing of all 100 machines, which should operational by July 2011. And if you would like to see one of the machines in action, check out this USPS promotion video trailer: .

Key FSS Benefits from the USPS perspective:

  • Substitute Automated Sequencing for Manual Labor
  • Manage Delivery Growth
  • Reduction in Future Delivery Vehicles
  • Reduction in Facility (Delivery Unit) Space Needs
  • Improve Processing Performance and Service
  • End-to-End Visibility
  • Create Lowest-Combined-Cost System

But why should I care and how am I directly impacted by FSS? Well if you mail flats, the USPS has new mail preparation standards that will have to be followed. The Postal Service gave “notice that FSS-based mail preparation requirements will become mandatory in the future; however we are currently not proposing a timeline for their implementation.” Optional FSS preparation can begin on January 2, 2011. The USPS posted an advance copy of the Federal Register Notice introducing new Optional Mail Preparation Standards for flat-sized Standard Mail, Periodicals and Bound Printed Matter prepared for delivery to ZIP Codes served by FSS processing facilities back on August 11, 2010,. A final FRN is scheduled to be released in mid-December, but additional Postal Bulletin updates and changes are expected to occur as the USPS ensures that PostalOne! and all of their systems can handle the new preparations. SAP Postalsoft Presort will support Optional FSS Preparation with Service Pack 6 releasing shortly in support of the January 2, 2011 USPS Rate Case. Presort 8.00c.06 will support FSS preparation through both Mail.dat 09-1 and 11-1 output.

The FSS preparation is optional and available for palletized bundles of Standard Mail, Periodicals, Package Services Bound Printed Matter (PSVC BPM) flats, and Mixed class co-mail. FSS does not support bundles placed in sacks or trays. FSS bundles are sorted to the FSS Sort Plan level by using data from the USPS labeling list L006, which is available to Postalsoft customers in your monthly directories. An Optional Endorsement Line (OEL) must be used to label each piece in an FSS bundle. You must barcode all the pieces in a FSS bundle. Automation and carrier route priced pieces must have either a delivery point POSTNET barcode or a delivery point Intelligent Mail barcode. Non-automation pieces must be barcoded to the finest extent possible. You can include the following types of priced mail within the same physical FSS bundle: Carrier Route Basic, Carrier Route High Density, Automation, and Non-Automation. Note: You cannot include Carrier Route Saturation priced mail within FSS bundles or FSS pallets. FSS bundles are then placed onto pallets according to the L006 tables into one or more of the following pallet-level separations:

     1. A 5-digit FSS-scheme ZIP Code combination (including one or more 5-digit ZIP Codes);

     2. FSS facility sort (all 5-digit FSS-scheme ZIP Code combinations processed within the same facility); or

     3. A sectional center facility (SCF) with FSS capability, when combined on pallets with flat-size mailpieces not intended for FSS processing.

FSS bundles can also appear on higher pallet levels, like AADC or NDC pallets, depending on the density and content of your mailing list.

What are the benefits and pricing of Optional FSS Preparation? Initial FSS preparation testing has shown very mixed results on whether you will actually save on postage. Results are very job specific and dependent on: the size of your mailing, the density of records in your list that are actually in areas serviced by FSS machines, and your job settings, like pallet and bundle mins & maxs. Postage is not the only factor to look at when determining whether or not to do optional FSS prep. You should also look at: additional preparation and production requirements, increased number of pallets generated, transportation costs, and other internal business practices affected by USPS requirements.

FSS pricing:

   Carrier route pieces

The software bundles carrier route pieces into FSS Sort Plan bundles with non-carrier route mail. Carrier route pieces retain the normal carrier route price if it meets the 200 piece or 50 pound minimum. All other pieces in the FSS Sort Plan bundle receive the 5-digit automation or 5-digit non-automation price. Carrier route sequencing standards do not apply to pieces within FSS Sort Plan bundles. The software sorts the pieces by 5-digit ZIP Code within the physical bundle.

   Periodical bundle charges

FSS bundles incur a 5-digit Outside-County bundle charge, although the bundle may contain pieces claimed at carrier route price. All FSS bundles are considered Outside-County.

   Periodical pallet charges

An FSS Sort Plan pallet incurs the Outside-County 3-digit pallet level container charge. An FSS Facility pallet incurs the Outside-County SCF pallet level container charge.


For more complete details on Optional FSS Preparation, please refer to the Presort 8.00c.06 Release Notes available starting Dec 13, 2010 with the SP06 release, and to the 23 August, 2010 Federal Register Notice at:


Even if you do not plan to do Optional FSS preparation at this time, more than likely your flat-sized mail will be processed on one of these new systems if you have pieces being delivered in an area serviced by an FSS facility. The USPS will try to maximize the use of these systems to sort as much of the flat sized mail that they can in order to improve the efficiency on their processing.


Please let us know if you plan to do Optional FSS Preparation in the near future or if you have any additional FSS related questions!

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