What Is a Unique Identifier (UID), and Why Is It Important?

Unique identifiers (UIDs) are specific codes or numbers assigned to objects, people, or data to distinguish them from others. They identify, track, and manage data in various industries, ensuring each item receives unique identification that differentiates it from any other item. For example, UIDs identify patients in health care, products in supply chain management, and Department of Defense assets. Their use is crucial in managing and organizing entities that might otherwise be challenging to distinguish from others. 

Learn more about unique identifiers and their use across various sectors to better understand their role and how you might use them.

What is a unique identifier (UID)?

A unique identifier (UID) is a sequence of characters or numbers that distinguishes a specific entity from others. UIDs are present and valuable in various fields for determining and identifying multiple entities. In database management, unique identifiers ensure each entry or information in a database is a one-of-a-kind. Each entry will have its own identifier, which is essential when dealing with customers, employees, and orders to avoid any issues or confusion. 

How are UIDs used?

Unique identifiers have many purposes and uses depending on the context and the industry you’re applying them to. Still, you can generally use UIDs to store and identify various data types. For example, in database management, unique identifiers distinguish one record from another, which allows data to be retrievable quickly and efficiently without ambiguity or confusion.  They can also link different records from different tables easily. 

Unique identifiers in access control systems approve or decline permissions to utilize resources. These systems ensure only authorized individuals can access the resources by checking the user's identity. 

Also, unique identifiers organize and track inventory items in inventory management, identifying and accounting for each item. In electronic transactions, unique identifiers, such as an ACH number, identify and track transactions, ensuring each transaction is unique and traceable to its source. In turn, this number increases transparency and reduces transaction errors and disputes.

Industries that use UIDs

Unique identifiers are essential for efficient and accurate data tracking and management in many industries. UIDs help ensure all customers, orders, or employees are the only ones in a system. The following popular industries utilize UIDs.

Health care

In the health care industry, UIDs identify important entities for a hospital or medical office to track. For example, the National Provider Identifier (NPI) allows medical systems and insurance companies to identify health care providers. Patients may receive unique identifiers, such as medical record numbers, to ensure providers and insurance companies can track their medical history and information accurately. Medical devices may receive assigned unique identifiers to track their accuracy and maintenance.

Academics 

UIDs identify and track academic publications, researchers, and institutions in academia. One commonly used identifier in academia is the Digital Object Identifier (DOI). The DOI is a unique identifier assigned to academic publications such as articles, various types of papers, and book chapters. This identifier ensures someone looking for the publication can easily find and cite it even if the URL or other access information changes. The publisher assigns the DOI and typically prints it on the opening page of the publication. It usually appears below the title or in the header or footer. 

Another example of a unique identifier used in academia is the ResearcherID. Individual researchers receive this unique identifier from the Web of Science platform. The ResearcherID allows researchers to track their own publications and citation metrics, and it can also identify and search for specific researchers. The ResearcherID links to other identifiers, commonly the ORCID (open researcher and contributor ID). This identifier also becomes assigned to individual researchers for usage across multiple platforms and systems. An ORCID iD also differentiates individuals with the same or similar names to avoid confusion. 

Business

In the business and finance industry, a unique BIN (bank identifier number) is the first four to six numbers on a credit card that identify the issuing bank. This number is crucial when deterring or determining identity theft or security breaches. The international bank account number (IBAN) is a unique identifier used to identify bank accounts in many countries. This number supports accurate and efficient transaction processing while minimizing the threat of errors. Financial institutions may also use unique identifiers like customer IDs to identify customers and their accounts.

Government

Unique identifiers recognize citizens, businesses, and government agencies in the government sector. For example, Social Security numbers identify US citizens, permanent residents, and eligible nonimmigrant workers in the United States. Other unique identifiers help track business licenses, tax IDs, voting, and more. They help ensure that government services are accurate and efficient without confusion or duplication.

Retail

Unique identifiers track inventory and sales in the retail industry. Barcodes and RFID (Radio Frequency Identification) tags are typical examples of unique identifiers in the retail sector. These identifiers allow efficient inventory management, tracking, and accurate sales reporting. Retailers may also use their own unique identifiers, such as loyalty card numbers or customer IDs, to track customer behavior and preferences.

Examples of UIDs

Many unique identifiers exist, and they have various contexts in which they are helpful. The following five examples help illuminate the use of UIDs in the real world:

• Patient ID: A patient ID is a unique identifier assigned to an individual patient in the health care system. The patient ID identifies and tracks crucial information related to a patient's records or current health across various health care providers and health care systems.

• School ID: A school ID, or student ID, is a unique identifier assigned to a learner by a school or educational institution. Schools and their systems typically use this identifier to identify students and track their academic progress, attendance, and other educational records.

• Universal Product Code (UPC): Every product in a retail store has a unique UPC, which includes a series of numbers to make up a complete barcode. The scanned UPC allows businesses to reference and analyze various metrics related to their inventory levels and overall sales.

• Vehicle Identification Number (VIN): The auto industry uses this unique identifier to identify vehicles, including cars, trucks, and motorcycles. Manufacturers, dealers, mechanics, insurance companies, and government agencies use VINs to track vehicle history and ownership.

• International Standard Book Number (ISBN): The publishing industry assigns this unique identifier to books and text-based publications. Each book has a unique 13-digit code used by publishers, booksellers, and libraries to manage and track books and facilitate the ordering, cataloging, and selling of books worldwide.

Continue learning about unique identifiers on Coursera

If you want to learn more about UIDs and their use in data management and other contexts, completing a course or receiving a relevant certificate is a great place to start. On Coursera, you can enroll in various data courses to get a feel for working with UIDs and more. For example, check out Foundations: Data, Data, Everywhere by Google to explore data analysis, become familiar with data visualization tools, and learn about essential concepts. 

If you are looking for an intermediate-level course, consider Database Management Essentials from the University of Colorado on Coursera. Enroll in this as an individual course or as part of the Data Warehousing for Business Intelligence Specialization, which can help you sharpen your skills in working with databases and data visualization.