Understanding USPS Delivery Performance


In the new world of omnichannel marketing, it’s critical to have accurate information related to your offline customer touch points.

Daunting as this information might be, competent mail service providers today have the experience, the data and the tools to help you build accurate and predictable mail distribution plans. The best can also help you deal with or overcome breakdowns in USPS delivery performance.

Understanding USPS Delivery Performance

The USPS has Service Standards, but what does that mean? The USPS has complete latitude as to how much or how little mail is in-home prior to the last day of the Service Standard. Usually, it is moving mail First In, First Out and as quickly as possible. The goal is to do this without using overtime, which was the focus of the Load Leveling initiative this past April when the USPS added a day to the Service Standard for Standard Mail delivered to Sectional Center Facilities (SCFs) on a Friday or Saturday. This latitude in the amount of mail delivered prior to the last day of the Service Standard means that mailers need to keep tabs on how the USPS is doing. How much mail are they able to process and deliver in one day, two days, three days and beyond?

Standards vary by mail class

Many ask, "What time does the USPS deliver?" The answer to that varies based on mail class. The Service Standard for First Class mail is perhaps the easiest to understand. The Critical Entry Time (CET) is the cutoff time for mail to be processed the same day it is dropped at the postal facility. It is expressed in 24-hour increments. For First Class Mail the CET is 19:00. Mail destined for ZIP codes within the SCF area that it is entered should be in-home next day. Mail destined for ZIPs within 300 miles of the entry point is to be in-home on Day 2. All other mail for the continental U.S. should be in-home by Day 3. Alaska and Hawaii mail should be in-home by Day 5. Note that in January 2015 the CET for First Class mail moves to 08:00. This essentially adds a full day to the Service Standards, as very few mailers will be able to deliver by that time.

The Service Standards for Standard Mail are also fairly straightforward when calculating USPS delivery times. If mail is delivered to a National Distribution Center (NDC) prior to 16:00, the Service Standard is 1-5 days from that date. SCF Mail delivered prior to 16:00 on a Friday or Saturday has a Service Standard of 1-4 days. And SCF mail delivered prior to 16:00 any other day of the week has a Service Standard of 1-3 days. If mail is delivered after 16:00, it is considered delivered the following day and does not make the cut off for processing that night. So 16:00 is the Critical Entry Time for Standard Mail.

Processing complicates things

On the surface, Service Standards for Periodical Mail are also easy to understand. Mail delivered to an SCF facility and addressed within that SCF area is to be in-home the next day. Mail delivered to an Auxiliary Distribution Center (ADC) or NDC, containing only mail for that area has a Service Standard of 1-2 days. But the CETs vary based on whether the periodicals can be processed by machine. This makes determining the dates the mail will be in-home more challenging.

The automated equipment for processing magazines, which the USPS calls flats, is called the Flats Sequencing System (FSS). It sorts the flats into the order the Postal Carrier walks his route. This sort eliminates the need for the Carrier to ‘case’ his mail prior to going out on his route, so it saves time on the Carrier side – theoretically allowing him more time to deliver more mail. Only certain zip codes are run on the FSS machines, as they cannot handle all mail in a facility, and many facilities do not even have one. Additionally, pallets of machinable flats destined for the FSS must meet critical pre-sort levels upon entering the postal facility. An FSS scheme pallet is a pallet of mail for one specific ‘scheme’, ZIP or set of ZIPs that the machine will process in one run. If the mail is for an FSS ZIP and on an FSS scheme pallet, requiring no bundle sorting, the CET is 11:00. If mail is for an FSS ZIP and on any other type of pallet, the CET is 08:00. The CET is 16:00 for non-FSS mail on a 5-digit level pallet and 17:00 for non-FSS mail on any other type of pallet.

The bottom line is that Periodical Mail has a 1-2 day Service Standard, but only for certain qualifying pallets delivered by a certain time. Very often it is actually 3 days before mail is in-home after delivery to an ADC or NDC and 2 days after delivery to an SCF.

Dealing with variability

Intelligent Mail barcode (IMb) scan data is the key to knowing how your mail is performing in the USPS system. The data provides both an overall view and performance by each USPS facility. If timing is critical to you, the variability in Service Standards can be problematic. And, as you might suspect, USPS performance is heavily influenced by volume fluctuations over the year.

When planning a mailing in June, one can expect a much higher percentage to be in-home just one day after delivery to an SCF than would be expected in November, when volume is much higher. More mail will shift to the later part of the Service Standard window in the heavy-volume months of September-December. Referencing past year’s data helps to determine what may occur the same week or month in the current year. But there are always variances.

Below is a general outline of how the USPS performs throughout a typical year and reflects general USPS delivery times:


Performance recovery from the holidays usually comes by week two. Delivery is not where it will be in June, but there is improvement.


Good delivery performance with only minor fluctuation.


The best delivery months of the year as volume is very low.


Expect some mid-month slowing as back-to-school catalogs cause some disruption.


First fall catalogs mail and cause a slight dip in performance, usually the first and third weeks of the month.


The week of Labor Day is usually a “good” delivery week, as the USPS prepares for it. The week following the holiday is the first slower week of the fall season. The last two weeks of the month usually are back to near-August levels.


Typically shows a drop in performance mid-month as Christmas catalogs mail heavily at this point. The last week of the month is usually one of the 3 slowest delivery weeks of the year due to the heavy volume.


Delivery from mid-October through the first week of December remains slow, but the slowest week is right after Thanksgiving when volume is extremely high as most catalogers mail their last big holiday push that week.


After the first week of the month, Standard mail delivery times increase because quantity drops precipitously. The USPS prepares for the First Class and Parcel surge and we typically see all mail move very quickly. The 2 days prior to Christmas typically slow down, as USPS focus shifts to that First Class mail. The period between Christmas and New Year’s is difficult – there are two days with no processing and in some years it’s even more depending on when Sundays fall. Distribution companies lose days they can ship and deliver to the USPS.


Maureen Noe is a Sr. Consultant in Quad/Graphics Postal Solutions group. With 23 years of mailing industry experience her focus is now on USPS mail performance and advising customers on mail distribution plans using data from tracking. Maureen is also a member of the USPS MTAC workgroup on IMb Tracing.

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