Puerto Rico ships as a US domestic destination with domestic postage, and its addresses differ from mainland ones in two ways. Many carry an urbanization line, URB plus the development name, between the recipient's name and the street. And the street type comes first as a Spanish prefix such as Calle or Avenida: 236 Calle Madrid.
An urbanization (urbanización) is a named residential development or sector. USPS Publication 28 calls the URB line an important part of the Puerto Rico addressing format. It goes on its own line directly under the recipient's name and above the house number and street.
Pub 28 also explains why: identical street names and number ranges can be found within the same ZIP Code, and then the urbanization name is the only element that correctly identifies the address. Its example is two addresses that both read 123 CALLE 1 in Bayamón PR 00961, told apart only by URB ROYAL OAKS versus URB HERMOSILLO.
Include the line whenever the customer gives you one, on its own line above the street. Do not guess an urbanization the customer did not supply.
Some development names stand alone and take no URB in front, including names that start with EXT (extensión), JARD (jardines), MANS (mansiones), REPTO (reparto), and VILLA (villas). Pub 28's example: write EXT VISTA BELLA, not URB EXT VISTA BELLA.
Many shipping and store platforms won't accept accented or Spanish-specific characters like ñ, é, í, ó, ú, or ü. Replace them with the closest plain Roman letters so the label prints and scans cleanly. If a name runs long, standard USPS abbreviations help it fit.
With an urbanization, four lines:
ANA ORTIZ
URB LAS GLADIOLAS
150 CALLE A
SAN JUAN PR 00926-3232
Without one, three lines:
LUIS TORRES
1234 CALLE AURORA
MAYAGUEZ PR 00680-1233
Both are Pub 28's own samples with generic recipient names, and Mayagüez written without its accent.
When in doubt, verify the full address with USPS before you print the label. Military APO, FPO, and DPO mail also ships on a domestic label with its own line rules; see how to format military mail addresses. Outsourcing the label step? Read about Simpl's ecommerce fulfillment service.