Understanding Alien Registration Numbers

In the labyrinth of immigration laws and regulations in the United States, one term that frequently surfaces is “Alien Registration Number” (ARN). To the uninitiated, this alphanumeric string might seem cryptic and daunting. However, understanding Alien Registration Numbers is crucial for immigrants navigating the intricate pathways of residency, citizenship, and legal status in the country. In this comprehensive guide, we’ll delve into Alien Registration Numbers’ significance, structure, and functionality, shedding light on their importance in the immigration landscape.

What is an Alien Registration Number?

An Alien Registration Number, sometimes abbreviated as ARN or A-number, is a unique identifier assigned to non-citizens by the USCIS. An ARN serves as a primary tracking mechanism for individuals who are not yet U.S. citizens but are lawfully present here. Essentially, an ARN functions as a digital fingerprint, enabling authorities to monitor and manage various aspects of an immigrant’s legal status and interactions with the immigration system.

Structure of Alien Registration Numbers

Understanding the structure of Alien Registration Numbers unveils insights into their composition and significance. An ARN typically consists of eight or nine digits, preceded by the letter “A.” While the length of the number may vary depending on when it was issued and certain immigration classifications, the general format remains consistent.

The first digit after the “A” typically indicates the decade in which the ARN was assigned. For instance, a number starting with “A0” might have been issued in the 1980s, while “A1” denotes the 1990s, and so forth. The subsequent digits represent various factors, including the order of issuance and specific immigration categories.

Purpose and Functionality

Alien Registration Numbers serve multifaceted purposes within the immigration system. While primarily used as a means of identification, it also has other uses. Primarily, it’ll be used for:

  • Identification
  • Immigration documentation
  • Law enforcement and security
  • Employment verification


Primarily, ARNs serve as a means of identifying and tracking non-citizens throughout their interactions with immigration authorities. Whether applying for visas, work permits, or green cards, individuals are required to provide their Alien Registration Numbers to facilitate processing and documentation.

Immigration Documentation

ARNs are integral components of immigration paperwork, appearing on various forms and applications. From adjustment of status petitions to employment authorization documents, these numbers link individuals to their respective immigration records, ensuring accuracy and efficiency in processing.

Law Enforcement and Security

Alien Registration Numbers play a crucial role in law enforcement and national security efforts. They enable authorities to monitor the movements and activities of non-citizens, facilitating compliance with immigration laws and regulations. Additionally, ARNs are essential for background checks and security screenings, ensuring that individuals meet eligibility criteria for residency and citizenship.

Employment Verification

In the realm of employment, Alien Registration Numbers are often required for verification purposes. Employers utilize these numbers to confirm the work authorization status of non-citizen employees, ensuring compliance with immigration and labor laws. Additionally, ARNs may be necessary for tax reporting and withholding purposes, further emphasizing their significance in the workforce.

Obtaining an Alien Registration Number

The process of obtaining an Alien Registration Number varies depending on an individual’s immigration status or other circumstances. In many cases, ARNs are issued as part of the immigration application process. For example, individuals applying for lawful permanent residency (green card) or certain visas are assigned ARNs upon approval of their petitions.

Additionally, individuals granted asylum or refugee status in the United States are also assigned Alien Registration Numbers as part of the resettlement process. These numbers enable them to access essential services and benefits, including employment authorization and social security benefits.

For those entering the country on temporary visas, such as student or work visas, an ARN may be issued upon arrival or as part of the visa application process. Regardless of the specific circumstances, Alien Registration Numbers are integral to maintaining legal status and compliance with immigration laws.

Importance of Maintaining Accurate Records

Once assigned, it is crucial for individuals to maintain accurate records of their Alien Registration Numbers. These numbers serve as lifelines within the immigration system, facilitating access to essential services and benefits. Failure to provide or update ARNs can result in delays, complications, or even legal consequences in immigration proceedings.

Furthermore, individuals should safeguard their Alien Registration Numbers, treating them with the same level of confidentiality as other sensitive personal information. Sharing ARNs indiscriminately can expose individuals to identity theft or fraud, potentially compromising their immigration status and security.


In the intricate tapestry of immigration regulations, Alien Registration Numbers stand as indispensable markers of identity and legal status for those who aren’t United States citizens. From identification and documentation to law enforcement and employment verification, ARNs play multifaceted roles within the immigration landscape.

Understanding the significance and functionality of Alien Registration Numbers is paramount for immigrants navigating the complex pathways of residency, citizenship, and legal compliance. By recognizing the importance of these unique identifiers and maintaining accurate records, individuals can navigate the immigration system with confidence and clarity, ensuring their rights and responsibilities are upheld in pursuit of the American dream.