X12 270/271 N301 (Address Information): Format, Values, and Testing Notes
N301 looks like the simplest element in the whole 271 response — it's just a street address — which is exactly why so few test suites bother generating anything beyond one tidy, textbook-formatted example.
N301 is the first element of the N3 segment in an X12 271 response — a free-form field that carries the primary line of a street address, such as the building number and street name.
What this element carries
Example
N301 = 482 Wexford Lane, the primary street line preceding the optional suite detail in N302. Synthetic 271 response data.
Where this trips people up
Because N301 has no internal structure, real-world values vary wildly — rural route numbers, directional prefixes like N or SW, apartment numbers crammed onto the same line instead of split into N302. Test data generated from a single clean street-address template never exercises these variations, so a system that handles "482 Wexford Lane" perfectly can still choke the first time it sees "Rural Route 4 Box 12" in production.