Code Books: The Key to Unlocking Your Data


Whether employed by spies to pass messages, spoken by Navajo soldiers to help the U.S. win World War II, or deciphered by little Ralphie’s secret decoder ring in the movie A Christmas Story, codes have long been used to conceal information.

In the credit union space, however, they are more often used to condense information into a simplified form for efficient processing. As a shorthand form of communication, codes bring the benefits of economizing the space needed to display information (on reports) and the time needed to share information (in data entry keystrokes).

Codes are everywhere

Codes have been integrated so much into our daily lives that we tend not to think about them unless we encounter an unfamiliar one. We usually just roll with the codes established by community consensus. If someone texts “OMG UR making me LMAO,” you are likely to understand without needing to consult a reference chart, since those codes are common knowledge amongst people navigating a digital world. Other codes may require a little more effort to grasp the meaning, like the cryptic or clever messages people manage to convey with the characters on a personalized license plate.

Many codes have been established by some kind of authority. When the Post Office Department introduced the five-digit ZIP code in 1963, they quickly realized that addressing equipment could not accommodate both that and the then used state abbreviations. So later that same year, they created the two-letter state abbreviations we know today.

Someone in the USPS must have decided that “MI” would be a good postal code for the state of Michigan, even though it might have been a good fit for Minnesota, Mississippi, and Missouri as well since those state names all begin with the letters “Mi”. However, those states have codes of MN, MS, and MO respectively. How do you know that? Well, you just know from experience or exposure somehow. Either that or you have a reference you can consult.

In the realm of data entry, codes provide a substantial standardization benefit, which helps explain why we employ them so frequently. For a moment, consider what kinds of results you would get if you left it completely up to the discretion of others as to how they input data. For example, how many ways could you say that someone’s job is waiting tables? Waiter, waitress, server, attendant, steward, host, hostess, serving staff, etc. come to mind. Add in the more ostentatious titles of some employers and the foreseeable misspellings and idiosyncratic abbreviations people will make in data entry, and you will soon have a data mess. How much simpler it would be to have just one fixed code covering that job type and all its variant names.

The magical code book

Chances are whatever data platform you are using to serve your members employs a lot of codes. If you are going to get serious about writing custom reports and doing data analytics work, your job will be a lot easier if you apply some effort to mastering those codes. However, even if you are your credit union’s Code Master and Configuration Guru, you are unlikely to remember the codes with 100% accuracy, given the great number of them and how much else in life is competing for bandwidth on your brain. You are going to need some help, and that’s where a code book comes in.

Codes make data more manageable, but codes themselves need to be manageable, and your code book will be just the tool to make that possible. Having one central point of reference for code information will save time and is highly preferable to racking your brain and searching in all the different nooks and crannies of your data processing platform for a code list. Given that each set of codes reveals what’s already expected and anticipated as an answer to some question, having a complete code listing will allow you to see the range of permissible values for something at a glance, which is no small thing.

Therefore, a good code book should assemble all your most important, relevant, and commonly used data codes, along with their meanings. Ideally, the code book will be easy to navigate, with links to and from a central index page. Each data point should have a user-friendly explanation of what it is, so non-experts can more readily get up to speed. A typical explanation might read like “This code classifies a loan according to the collateral attached to that loan, when applicable.”

When it comes to your core processor’s data platform, you will find that some codes are under your control, while others are maintained by the core processor. Any which are established by an outside government agency would just be passed through by your core processor. As you build your code book, it will become clearer which codes are which. Consider indicating each code’s origins in the code book, so people can know what may be altered and what you are stuck with.

Some credit unions are continually innovating and updating the codes they control each month as they respond to credit union needs and market demands. Other credit unions have little change month-to-month. Is your accounting department adding new general ledger accounts on the sly? Did someone add a new loan or deposit product and forget to inform everyone? By maintaining your code book, you will keep your finger on the pulse of your credit union to know how quickly things are changing, instead of being blindsided by it. While many code lists do not change, a series of custom reports can allow you to easily update the code lists which do change, preferably at least once a month or so.

Start building your book!

When done right, the cost of time and effort to build and maintain your credit union’s code book is a worthwhile investment. All levels of your organization will be able to share in the benefits. If you store a copy of the code book in an accessible place, staff members can self-serve on the information therein, instead of tying up the time of others. Having more eyes on your codes will also expose the gaps in your coding, allowing you to have conversations like “hey, we don’t have a code for this possibility and we really should.” More general knowledge of available codes will also help prevent the creation of multiple codes for the exact same thing by different people with configuration access.

In short, a code book will improve your work life and those of your co-workers, and it may even preserve your sanity. So, why haven’t you built it yet? Get cracking!


  • George Hopper

    George Hopper is a Data Analyst at BlueOx Credit Union who has been helping credit unions measure success and their progress toward it for the last ten years.

Your email address will not be published. Required fields are marked *