Every individual in the world is unique, which helps distinguish one person from another. Uniqueness also extends to physical and digital objects, enabling directed interaction or management. When you use a unique identity (UID), it’s easy to distinguish objects and help the selection process. You don’t need other functional characteristics or attributes. This helps speed up database searches and reduce the code length. It also allows companies to develop more efficient solutions.
UIDs enable effective tracking, monitoring, inventory checking, and analytics. They also help you select identical fungible objects, like banknotes. To achieve this, UIDs use unique alphanumeric characters with the object quantity dictating a string’s length. The character length also depends on the company’s security policy. UIDs also help reduce errors in data entry and coding language.
In this article, we’ll look at what unique identification is and how it works in a business environment. That, in turn, will help you optimize your data solutions.

What Is a Unique Identifier (UID)?
A unique identifier is a distinct alphanumeric string value that a computer algorithm assigns to an entity in a system. Here, an entity can be any object, component, or subcomponent. Objects are also everywhere and include; users, files, data records, organizations, or anything else.
The algorithm usually adds new UIDs incrementally. The process is also automatic, following a rule. That said, systems that allow manual user entry can cause duplications or inconsistencies. This, in turn, also impacts your ability to search and retrieve objects. A more adverse effect is when logical scripting errors occur with data inconsistency or duplication, leading programs to crash.
The US Department of Defense (DoD) was the first to use modern unique identifiers. The department reaped the benefits, achieving better inventory processing and equipment accountability. That also helped reduce theft, speed up troop deployment, and achieve leaner supply chains.
Physical interfaces and user-friendly pseudonyms also help you interact with UIDs. Barcodes, QR codes, IPv4, and IPv6 DNS lookup names, are just some examples. These also link physical assets with digital management systems.

Now that you know what UIDs are, let’s look at how companies determine the unique identifier’s length.
Determining the UID Size
It’s often up to companies to decide on the UID’s length. A company has to balance an unwieldy number and not having enough UIDs.
That leads many companies to turn to standards and umbrella companies to determine the UID length. IEEE, for example, bases its unique identifier standards on industrial research. The MAC address protocols use the information found in IEEE network standards to define the UID format.
IEEE suggests a 2^24 size for large MAC addresses, 2^20 for medium, and 2^12 for small MAC addresses. Since all networks follow these standards and protocols, internet connectivity is possible.
Sometimes a company needs to create a custom UID. That helps users better relate to the UID when using it. Engineering PLM solutions, for example, can provide custom or default UID options. That also helps companies meet project requirements from third parties, like the DoD. For security applications, the UID length balances security, use, and scalability.
Now you know how to construct UIDs, let’s move on to discuss their applications in the next section.
UID Applications
UID codes are everywhere, and you can use them in almost every digital activity today. Let’s take a look at the top 4 most common uses.
1. Website or Service Registration
When you register for a website or online service, you create a unique username and password. In turn, the system creates a UID for every registered user. This UID acts as a container for user attributes, including username and password. That helps the company track what you do on their website to provide personalized services. Technical issues and other activities all refer to the UID.

2. Database and Spreadsheets
Databases and spreadsheets contain a primary key field to identify a record or cell. This UID type also helps you sort records, filter them, and find what you want.
Let’s say you work at a company and want to know your exact designation within the company. You’ll go to the company’s internal portal and enter your employee ID. In the background, the application runs an SQL query with your employee ID as the primary key. That returns your designation from the database, displaying it on the portal.
Here, the primary key, or your employee ID, is the UID. This key distinguishes you from other employees in the database. All your information also links to this key for quick sorting and search results. That helps companies organize data and retrieve it quickly.
3. Supply Chain and Inventory Management
In this case, a manufacturer uses UIDs to mark a product. Then, they use the UID they assign to track the product throughout its lifecycle. It also helps retailers manage their inventories and offer after-sales tracking.
4. Patient Records
Hospitals create a UID for each patient to track their treatment progress and medications. Unlike other unique identifiers, mandates from HIPAA ensure continuity across all medical facilities.
As you can see, UIDs have endless applications, with my list above serving as a mere introduction. UIDs are useful due to their flexibility. Such flexibility allows many applications to use the same UID.
Next, we’ll check some extensions you can also easily apply to more complex operations.
UID Examples
Using UIDs for every object has taken a whole new meaning in recent years. That’s resulting from business automation through integration. Some prominent UID examples are found in the following table:
UID Name | Use Case |
MAC Address | Recognize hardware in a network |
Bank Identifier Code (BIC) | Identify a bank or a financial institution |
Service Set Identifier (SSID) | Identify a wireless LAN |
Global Unique Identifier (GUID) | Identify Microsoft objects, like an Excel spreadsheet |
Universal Unique Identifier (UUID) | Identify an entity on the internet |
Uniform Resource Locator (URL) | Return a webpage after identifying it during queries |
Uniform Resource Identifier (URI) | Identify different content on the internet |
As you can see in the table, you can apply these UID extensions to different objects and entities. The above list isn’t exhaustive, but it shows how widespread and integrated UIDs have become and their versatility to represent any object.
Final Thoughts
Unique Identifiers are alphanumeric characters that uniquely identify an object or entity. These include users, resources, web pages, networks, or just about anything you want to select, track, or count. You’ll encounter UIDs when using backend components or frontend user interfaces. No matter where you find them, remember a UID policy needs to balance ergonomics, security, and relatability.
FAQs
Are UID, IUID, and UII the same?
No, they’re different. The Department of Defense (DoD) uses them to classify government property. Item Unique Identification (IUID) stores information on tracking and maintaining assets. Unique Identification (UID) is the physical unique item number. Finally, Unique Item Identifier (UII) is the corresponding database entry. The difference stems from the DoD’s procedure to use three different data workflows for its applications layer.
Are all UIDs alphanumeric characters?
Yes, all UIDs are alphanumeric characters, even if you don’t see them. Barcodes, QR codes, catalog numbers, and accession numbers use these characters. That said, graphical interfaces help create a better user or technology interface with the UID system.
Will all UIDs have the same character lengths?
Yes, if you’re looking within a specific context. For example, all the books in a library can have a certain character length to uniquely identify them. That said, all the devices in a marketing company need not have the same digit length. In this sense, the character length in a UID depends on your company’s business requirements.
Is UID mandatory?
UIDs are often not mandatory but are helpful to identify and track objects in your company. In some cases, though, it’s mandatory. That’s usually when dealing with identical (fungible) objects, like currency. That enables systems to select objects, like banknotes, and track them. Standards, like HIPAA, also mandate a unique ID for healthcare solutions. That’s useful for quick access to patient records at different sites or departments.
Are cryptographic hashes a UID?
Yes, cryptographic hashes are UIDs. In a hash, you input a value through a mathematical algorithm to get an output. If you send the same value through the same algorithm, you’ll get the same output. That said, no one does this in the real world. That means every unique input gives a unique output, and, in this case, cryptographic hashes are a UID and generate them.
Are barcodes and QR codes the same?
No, barcodes and QR codes are different, though they can represent the same UID. Barcodes are vertical lines with thicknesses and spacing between lines representing a value. Companies often use them to represent a UID. A QR code provides better data density by using vertical and horizontal axes. They’re the same in that your system needs to read them optically to enable an application to query the UID.
Resources
TechGenix Article: W2K Loses GUID Through Memory Leak
Learn what happens when W2K has no more memory here.
TechGenix Article: What Enterprise Must Know About Data Lakes
Click here to know everything about data lakes.
TechGenix Article: Static vs Dynamic IP Addresses
Read this article to understand the differences between static and dynamic IP addresses.
TechGenix Article: Daily user management tasks for a Linux administrator
Learn about all the daily management tasks a Linux administrator needs to complete here.
TechGenix Article: Schema Object Identifiers
Learn all about schema object identifiers here.
TechGenix Article: HIPAA IT Compliance
Click here to learn what HIPAA IT Compliance is.