Recently in Postal Address Standards Category

By David Loshin

The address may be complete, all the elements may be valid, the ZIP+4 is the right one, and all values conform to standardized abbreviations ... and still be incorrect if the recipient is not associated with the address!

This is the bigger challenge with address data quality, since address correctness or accuracy is a factor of real-world events that are not necessarily synchronized with your databases. Some level of control is again served by the Postal Service through the NCOA (National Change of Address) data set that is licensed to tools providers.

Checking against the NCOA data set will notify you if an entity linked to a location has self-reported a change of address, and this accommodates a large portion of the address correction issues. However, there are estimates about the percentage of people that moved, and I recall reading a Census Bureau press release about their 2006-2007 statistics noting that 14% of the population moved over the year.

Not all changes propagate to the NCOA file at the right time, and it may take a while before all consumers of that data actually synch up with the NCOA data set. Even if you do a quarterly review, if we trust that 14% statistic, then there is a pretty good chance that by the end of the quarter you will still have a 3-4% inaccuracy rate for mapping entities to locations.

And there are other considerations that are not incorporated into this calculation. For example:

• Individuals change jobs and therefore change business addresses
• Third-party data vendors incorrectly link individuals to locations
• Miskeyed data
• Purposely incorrect data
• Propagation of legacy addresses overwriting updated addresses

This a small sample of challenges. But what it means is that there are many aspects of assessing and assuring the quality and correctness of addresses, and it may be worth reviewing the ways that your organization verify, validate, standardize, and correct location data!

By David Loshin

The next paragraph provides some additional details:

 "A standardized address is one that is fully spelled out, abbreviated by using the Postal Service standard abbreviations (shown in this publication) or as shown in the current Postal Service ZIP+4 file."

A large part of the remainder of the document guides what is valid and what is not valid, as well as the postal standard abbreviations (as mentioned in the definition of standardized). So an address must be complete, which by definition implies that it can be matched with current Postal Service ZIP+4 and City State files.

This match is to obtain the ZIP+4, so the implication is that verification means that a complete address matches the USPS files and has the correct ZIP+4. The address components must be consistent with the postal standard in terms of valid and invalid values. For example, a street address cannot have a number that is outside the range of recognized numbers (that is, if the USPS file says that Main Street goes from 1-104, an address with 109 Main St is invalid). So validation means that the street address is consistent with what is documented by the USPS files. Standardization is also defined by the above reference: it is spelled out, and uses the USPS standard abbreviations.

In turn, the process for address quality would be to:

1) Ensure the address is complete.
2) Ensure that the address values are valid by checking it against the USPS files.
3) Verify the address's ZIP+4 by matching against the USPS fles.
4) Standardize the address according to the USPS standardized abbreviations.

Postal Reform legislation passed the Senate this month, but according to the Postal Service (and who should know better?) S. 1789 falls disappointedly short of restoring the USPS to financial viability.

For the past two years, the Postmaster General and the Board of Governors of the USPS have worked diligently preparing a comprehensive five-year plan to profitability that would enable revenue generation and achieve cost reductions of $20 billion by 2015 - restoring the Postal Service to long-term growth. The USPS is currently losing $25 million a day and has a debt of more than $13 billion.

Following the two days of sessions it took to vote on all the amendments in the bill, PMG Patrick Donahoe stated: "Based on our initial analysis of the legislation passed today, losses would continue in both the short and long term. If this bill were to become law, the Postal Service would be back before the Congress within a few years requesting additional legislative reform."

So where do we go from here? To the House of Representatives with an entirely new bill - H.R. 2309 - and with their own ideas for Postal Reform.

In the meantime? Take a look here at S.1789 to see exactly what the Senators voted for, and against, and then review the USPS Plan to Profitability - 5 Year Business Plan ... It's a good read. After that ... well, we'll keep you posted.

By David Loshin


And there are many references to operations or transformations performed on addresses, mostly with the intent of improving the quality of the address.

Curiously, there are a number of different terms used to refer to these different transformations: validation, verification, standardization, cleansing, correction. I am sure there are others. But what do all these things mean? And why are these different terms used if they mean the same thing?

The first step in exploring the answer to this question is reflecting back on the nature of deliverable addresses. When an item is sent to an addressed location, there are some core concepts that need to be right:

1) The item must be directed to a specific recipient party (either an individual or an organization).
2) The address must be a deliverable address.
3) The intended recipient must be associated with the deliverable address.

In addition, there are certain incentives provided to senders when the addresses are completely aligned with the Postal Standard, adding one more concept:

4) The delivery address must conform to the USPS standard.

These directives provide us with some material with which to work for differentiating the different terms used for postal data quality. More next week...

By David Loshin


This is all well and good as long as you use the standard. The problem occurs when, for some reason, the address does not conform to the standard. If the address is slightly malformed (e.g. it is missing a postal code), the chances are still good that the location can be identified. If the address has serious problems (e.g. the street number is missing, there is no street, the postal code is inconsistent with the city and state, or other components are missing), resolving the location becomes much more difficult (and therefore, costly).

There are two ways to try to deal with this problem. The first is to bite the bullet and treat each non-standard address as an exception, forcing the delivery agent to deal with it. The other approach attempts to fix the problem earlier in the process by trying to transform a non-standard address into one that conforms to the standard.

Address standardization is actually not that difficult, especially when you have access to a good standard. At the highest level, the process is to first determine where the address does not conform to the standard, then to standardize the parts that did not conform.

If you recall from my previous post, an address captures the incremental knowledge to resolve the location, and we can use this fact plus the information provided in the standard to consider ways to fix non-standard addresses. Each component has its specific place inside the address, and there are standards for abbreviations (such as ST for "street," or AVE for "avenue") as well as for common terms (such as ATTN for "attention").

One can define a set of rules to check if the address has all the right pieces, if they are in the right place, and if they use the officially-sanctioned abbreviations. You can also use rules to move parts around, to map commonly-used terms to the standard ones, and use lookup tables to fill in the blanks when data is missing. So in many cases, it is straightforward to rely on tools and methods to automatically transform non-standard addresses into standardized ones.

By David Loshin


How can I communicate to the agent where the item is to be delivered? From the modern day perspective, it should be obvious: you only need to provide the street address and you expect that the agent will be able to figure it on his own.

However, this begs the question, specifically because we never think about the existing framework of standards that has evolved around any communication system (whether that is for physical package delivery, connecting telephone calls, or sending emails).

We expect that the delivery agent will be able to figure out how to get to a location because the standard address format contains a hierarchical breakdown for refining the location at finer levels of precision. In the US, an address contains a street name and number, as well as a city, state and a postal code. The refinement can begin with the state, then resolve down to the city, and then the postal code.

By the time you have resolved down to that level, one is likely to be able to easily find the street, and the specific location is determined using the street number.

This process works in the US because there is a postal standard, and in fact the driving force behind addressing standards is the need for accuracy in delivery.

Following the standards ensures that anyone reading an address has enough information to be able to find the addressed location. In the US, there is actually a very comprehensive standard, called "Publication 28," and it describes all the gory details. And in my next few posts, we'll look at some interesting aspects of addressing, address standards, and the concept of "location."