Tracking Flats – How’s USPS Doing with that Lately?
March 29, 2024   Dave Lewis

Since the earliest days of mail tracking, back when cavemen chiseled postnet barcodes onto the walls of their caves, tracking flats has been a challenge.  Letters track great – generally – but flats…not so much. Are they as difficult to track as advertised?  Are they getting better?  Worse?

First, let’s get some definitions out of the way.  Apologies to my fellow postal nerds who have this stuff down cold.

When I say letters, I’m talking about letter-size mail.  It can be a folded self-mailer, a card, or, yes, an inserted envelope – the key is size.  Generally speaking – because USPS has exceptions to everything – a letter is a piece of mail that is less than 6 1/8” tall x 11” long, and less than ¼” thick.  This can vary for envelopes vs single sheet self-mailers vs folded self-mailers, but those are generally letter dimensions. 

A flat is a piece of mail that exceeds those dimensions.  Typically, flats are magazines, catalogs, and 9 x 12 envelopes.  Flats can come in a variety of sizes and orientations, so they are much more difficult to process on automated equipment. 

Letters are most often sorted on high-speed sorting equipment at the Postal Service.  As they run through these machines, the Intelligent Mail barcode is scanned and used for both sorting the mail and capturing tracking data.  Because almost all letters run through this equipment, the data is excellent for tracking letters.  It is easy to determine when letter mail is being delivered, and very accurate. 

Flats are more challenging.  Many flats never go through sorting machines.  Large quantity mailings of flats may be routed directly to delivery units within a bundle or a pallet without ever running through a machine, so no direct scan may be available.  However, containers and bundles are scanned, and can be matched back to the mail piece.  As scanning pallets and bundles is most often a manual process, scanning is less than perfect.

Because of these differences in handling, a mailer can typically expect a scan rate of close to 99% or better on a good quality letter-size piece with a good, readable barcode.

Flats…not so much.  So, the question is, just how reliable is flats tracking?

At SnailWorks we monitor all the flats we are tracking and measure the scan rates.  We have been doing this for several years now.  The report takes the number of flats we tracked in a month, and measures what percentage received any scans at all, and what percentage were tracked to delivery.  We also break them down by type of sortation, based on the barcode ID in the IMb.  Here’s a report from August, 2022: 

So, in this case, out of 22 million pieces tracked, 96% of them got at least one scan – typically an induction scan when the Postal Service takes possession of the mail.  This is important in documenting that the mail was indeed given to the Postal Service, and the date this occurred.  68% were tracked to delivery.  Of those, most categories did much better.  Carrier route mail didn’t do as well, which can be typical.  August 2022 was also an election year, and political campaigns love flats, so that may have contributed to a disappointing carrier route percentage.

Now, here’s a report for February, 2024:

Hmm…not really much different.  It’s maybe a little better if anything.

The moral of the story?  While not quite as good as tracking letters, scan rates on flats remain OK and very valuable.  Particularly for agencies with multiple vendors (We’re looking at you, political consultants) the possession scan is critical to making sure your vendors are performing and proving the same to your clients. 

It is no secret that USPS is having some issues, but at least we seem to be getting the data we need to keep it under control.  Mailing flats?  Track ‘em!