Understanding Why Some Pieces in Your Mailing Weren’t “Delivered”
October 24, 2022   Dave Lewis

So few things in life are 100% - including mail pieces tracked.   Mail tracking jobs showing a scan rate of 100% are a rare sight.  A letter-size mailing with a very clean list and quality barcodes may well show more than 99% of the pieces tracked to delivery, but almost never 100%.  Understanding why some pieces don’t show as “delivered” can be important in measuring many mail quality issues. 

In the coming months, we will be releasing a report that analyzes pieces showing as undelivered and categorizing them.  We expect it to be very helpful in identifying and correcting excessive undelivered issues.  In the meantime, the data you need to measure the issues are in plain sight. 

Please note that when we talk about “undelivered” mail in this context, the mail is not necessarily undelivered.  A more accurate description is “not tracked to delivery.”  It may have been delivered – we were just unable to identify scans that showed it.  I use the term “undelivered” in this article for convenience.

These “undelivered” pieces may seem to be a mystifying aspect of mail tracking but it’s not really a mystery.  And just because a piece doesn’t show as being delivered doesn’t mean it wasn’t delivered – it just didn’t get scanned to delivery.  The primary reasons we see for pieces not tracking to delivery:

  • Not every piece was mailed – spoilage, QC pulls, last minute deletions
  • A barcode defect can cause missing scans.  The wrong serial number was printed in the IMb – inkjets can miss a bar, a window can block a barcode from fully showing
  • Undeliverable As Addressed – people move a lot.  The NCOA processing that happened last week will be wrong this week.  Someone may not have filed an address change when they moved.  As soon as we see address change processing, we call it “undelivered”
  • There may be a defect in processing at USPS – maybe a double was pulled, a piece got misplaced

Understanding the details of your “undelivered” mail can be valuable in helping to improve your processes and minimize wasted postage.  Here’s how we look at it:

  • For letter-size pieces, if your scan rate is 97% or better, you are unlikely to get much improvement.  Identify the pieces that have a PARS flag and check the addresses.  If the “undelivered” pieces are concentrated in one area, you may want to investigate further – we can help.
  • For letter-size pieces, if your scan rate is between 90% and 97%, you will want to check on the undelivered pieces more closely.  Are there a lot of PARS pieces?  This could mean list issues.  If it’s a rented list, you may want to investigate it.  Are there a lot of pieces with no scans at all?  This may indicate spoilage, or barcode defects.  A lot of pieces with just one scan?  Mail may be stuck in the postal system. 
  • For letters, if your scan rate is below 90%, any of these issues could apply, as well as a more challenging piece to run through equipment.

Here’s what we do when we get questions on the undelivered portion of a mailing:

  • We look at timing.  Are we looking before the mail has had a chance to deliver?
  • We look at a few successful pieces – is there anything unusual about the path the piece traveled?
  • We ask for a picture of a piece from the mailing, with a visible barcode.  Are there possible design issues?
  • We look at PARS quantity.  Was too much of the mail UAA?

Depending on the scan volumes and issues we discover, we may dig deeper into the mailing, maybe enlisting the assistance of the Postal Service.  We can almost always figure it out.

Of course, sometimes there are just ghosts in the machine.  We just must learn to live with them and carry on…but not very often.  We – almost – aways find our mail.