Short answer

The correct format

Put the recipient or attention line above the company name when a specific person should receive the letter. Write the street address and suite on the next line, then the city, two-letter state abbreviation, and ZIP Code. Place your return address in the upper-left corner and postage in the upper-right.

Copy-ready example
ATTN MORGAN RIVERA
NORTHSTAR DESIGN CO
850 MARKET ST STE 240
SAN FRANCISCO CA 94102

Choose the right recipient line

Address the letter to a named person when you know who handles it. A full name and useful role or department reduce the chance that the envelope will sit in a general mailroom queue.

If you do not have a name, use a specific department such as ACCOUNTS PAYABLE or HUMAN RESOURCES. Avoid vague labels such as “To whom it may concern” on the outside of the envelope.

Order the company and delivery information

Keep the recipient, organization, street address, and city line together as one block. The company name belongs between the attention line and the delivery address.

Add a suite number at the end of the street-address line when it fits. If it does not fit, place the suite line directly above the street address. This follows the same secondary-unit principle used for apartment addresses.

  • Recipient name or attention line
  • Company or organization name
  • Street address + suite
  • City + state abbreviation + ZIP Code

Format the return address for business mail

The return address identifies the sender and gives undeliverable mail somewhere to go. Put it in the upper-left corner of the envelope. Include a company name when that will help returned mail reach the right team.

A department can be useful for invoices, applications, legal correspondence, or customer returns. Keep the return block smaller than the delivery address so the intended recipient remains visually clear.

Final checks before mailing

Confirm the recipient spelling, suite number, ZIP Code, and current business location. Companies move, consolidate offices, and use different addresses for payments or returns, so an old address from a previous email may no longer be correct.

  • Use the address supplied for this specific purpose
  • Remove unnecessary punctuation
  • Do not place logos or notes in the barcode area
  • Check current postage for the envelope size and weight

Official references

Reviewed against the postal guidance listed below. EnvelopeFormat is independent and is not affiliated with USPS or Royal Mail.

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