For a care-of address, ask who will receive mail for the intended recipient. For an attention line, ask which person or department inside the organisation should receive it. Neither C/O nor ATTN replaces the street address, unit or ZIP Code.
The next question is where those details belong. A postal address block, a carrier’s example and a website’s input fields are not necessarily arranged the same way.
Whose name follows C/O?
C/O abbreviates care of. The Tufts International Center’s US mailing guidance illustrates the intended recipient first, followed by a care-of person or organisation.
This schematic follows that arrangement. Every bracketed item is a placeholder, not a verified address or something to copy onto a real shipment:
[INTENDED RECIPIENT]
C/O [PERSON OR ORGANISATION RECEIVING FOR THEM]
[ACTUAL STREET ADDRESS AND REQUIRED UNIT]
[CITY STATE ZIP]
Keep the two roles distinct. Confirm the recipient’s details and the receiving arrangement before using someone else’s address; knowing an address does not establish that its occupant accepts mail for you.
Treat this as a sourced example, not a universal instruction for every carrier’s form.
Does ATTN go above the company name?
For the mailpiece layout in USPS Publication 28 §214, the attention line precedes the firm name:
ATTN [PERSON OR DEPARTMENT]
[COMPANY OR ORGANISATION]
[ACTUAL STREET ADDRESS AND REQUIRED UNIT]
[CITY STATE ZIP]
There is a real difference between carrier examples. FedEx’s package-addressing guide currently shows the company first and the ATTN recipient second in its business example.
Check the selected service and the receiving organisation’s instructions. Do not combine pieces of different examples and assume the result is a universal US address standard.
Match the fields to their purpose
Use the website’s instructions and inspect what it saves. These are checks, not promises about how every form prints a label:
| Field | Check |
|---|---|
| Recipient / Name | The intended recipient remains identifiable. Do not turn the host’s name into the recipient’s surname merely to fit another line. |
| Care of / C/O | If explicitly provided, follow its instructions for the actual receiving person or organisation. |
| Attention / ATTN | Keep the named person or department without losing the company. |
| Company | Use the actual organisation where applicable; do not invent one to fill an optional box. |
| Apt / Suite / Unit | Preserve the real unit designation. A care-of name is not a unit number. |
| Address Line 2 only | Do not assume it supports C/O correctly. Check the help and output; ask the website or carrier if the mapping is unclear. |
Do not delete a real unit or substitute another address to satisfy validation. See the US address structure guide for delivery-address components. If the destination is a mailbox, check PO Box versus street address: adding C/O does not change its address type.
Check the saved record and label
Compare the recipient, care-of party or department, company, street and unit with the original details. Look for missing lines, truncated names or a department overwriting the unit. Inspect the final label when available; an order confirmation proves only what that screen displays.
USPS Business Mail 101 separates name/attention and company information from the delivery address below them. A field labelled “Line 2” does not tell you where it will appear in that printed arrangement.
Delivery to an organisation is not proof of handover to the named person. USPS DMM 508 addresses institutional delivery separately; confirm internal collection arrangements with the organisation. Writing C/O is not itself a mail-forwarding request.
We checked published guidance, not live merchant forms or actual deliveries. Generated address data on this site is for learning and software testing. For real mail, use the recipient’s confirmed complete details; correct formatting alone does not guarantee delivery.