Certified mail guide
How to Address Certified Mail to an Apartment or Suite
An apartment or suite number can be essential to getting a letter to the right door. Use the recipient's complete address, check the unit and ZIP Code, and review both addresses before paying for Certified Mail.
Why the unit matters
Certified Mail adds a mailing record and tracking to an eligible letter, but it does not repair an incomplete delivery address. USPS says the correct apartment or suite number helps a piece reach the right location. If the destination has a unit, ask the recipient or use the address they supplied rather than guessing. Keep the unit with the street address when you enter the recipient in a mailing form.
An address checker may standardize spelling or a ZIP Code. That does not mean it has confirmed an apartment or suite number you never entered. Pause if a suggested address changes or drops a unit, and compare it with the recipient's instructions before continuing.
Where to put the apartment or suite number
USPS recommends an applicable secondary designator such as APT, STE, RM, or FL with its number. The preferred placement is on the same line as the street address, after the street information. If that does not fit, USPS says it may go on the line above the street address. Do not put it below the street line.
The example below illustrates the format; it is not a real address. Preserve the recipient's actual unit label and number. A business address may need a suite, floor, room, department, or attention line. Confirm which details the recipient requires.
Recipient Name 123 Example Street APT 4B City ST 12345
Check the city, state, and ZIP Code
Write the city name correctly, use the two-letter state abbreviation, and include the ZIP Code. USPS recommends ZIP+4 when known, but a five-digit ZIP Code is still useful when ZIP+4 is unavailable. If you are unsure of the city spelling or ZIP Code, use the USPS ZIP Code Lookup before sending.
Be careful with an address suggestion that corrects the street or city but leaves the unit uncertain. Review each part of the result. An exact unit matters more than accepting a tidier-looking line that no longer matches the recipient's directions.
Review the return address too
Provide a return address where you can receive mail if the piece cannot be delivered. Check its street, unit if applicable, city, state, and ZIP Code just as carefully as the recipient address. USPS places the return address in the upper-left area of the envelope; an online mailing service prints that block from the information you provide.
Before payment, compare the sender and recipient blocks side by side. Look for transposed digits, a missing apartment or suite, a wrong directional, or a ZIP Code that belongs to another city. If the site proposes a standardized address, review it before applying it. Do not assume that a corrected address guarantees delivery.
After sending, keep the record with the address you used
Save the final address you approved, your order confirmation, and the USPS tracking number together. A tracking number can exist before USPS has scanned the letter; check the actual USPS event before treating it as an acceptance or delivery record.
LetterBeacon lets you review sender and recipient addresses and any suggested correction before payment. Keep a copy of the version you approved.
For help interpreting the first tracking update, read what “USPS Awaiting Item” means.