Correctly Addressed

Components

How to address an envelope using c/o

Write the recipient full name on the first line, then C/O and the name of the person or place holding the mail on the second line, then the street address, then city, state and ZIP: JANE DOE, C/O ROBERT SMITH, 123 MAPLE ST, PORTLAND OR 97201. C/O tells the carrier and anyone else at that address that the recipient does not live there permanently, and it works through a person, not a company, which is what separates it from ATTN.

Checked July 30, 2026/7 min read

Claire Post

Written by Claire PostReviewed against USPS Publication 28

What is on this page7 sections
  1. 01Step by step
  2. 02Real examples
  3. 03Quick reference
  4. 04Special cases
  5. 05Key terms
  6. 06Check before you mail
  7. 07Questions people ask

“Care of” is one of the oldest conventions in mail addressing, and it solves a problem that is easy to describe and easy to get wrong in practice: how do you address a letter to someone who does not live at the address you are sending it to?

The format itself is simple, two lines, recipient name then c/o and an intermediary name. What trips people up is not the format, it is knowing when c/o is even the right tool. A hotel guest, a college student in a dorm, a deceased person estate, and a child too young to manage their own mail are four completely different situations that all use the identical c/o structure, and each one has a wrinkle the basic format does not warn you about.

Step by step

  1. Start with the actual recipient name

    The person the mail is for, not the person holding it for them. This is the first line, always.

  2. Add C/O and the intermediary name on the next line

    C/O, then the name of whoever is physically receiving the mail on the recipient behalf.

    SARAH CHENC/O MICHAEL CHEN800 ELM AVEAUSTIN TX 78701
    CorrectStandard c/o format, someone staying at another person home.

  3. Finish with the street address of where the intermediary actually is

    Not the recipient usual address. The street line belongs to wherever the c/o person or place physically receives mail.

  4. Know that c/o is for routing through a person, ATTN is for routing through a company

    If the address on the envelope belongs to an individual or a household, use c/o. If it belongs to a business or organization, use ATTN instead.

  5. Leave your own return address unaffected

    C/O only changes the delivery address block. Your return address in the top left corner stays exactly the same as it would on any other letter.

A few real examples

The steps above cover the rule. These show it applied to a spread of real situations, so you can match yours to the closest one.

JAMES WARRENC/O HILTON DOWNTOWN AUSTIN500 E 4TH STAUSTIN TX 78701
CorrectMail forwarded to someone at a hotel. Confirm the hotel will hold personal mail before using this.
EMMA PATELC/O THURSTON HALL FRONT DESK2250 I ST NWWASHINGTON DC 20052
CorrectA college student living in a dorm. Check the university mail policy first, many route through a central mail room instead.
ESTATE OF HAROLD JONESC/O MARGARET JONES EXECUTOR47 BIRCH LANESPRINGFIELD IL 62701
CorrectMail to a deceased person estate, addressed to the executor.
THOMAS MILLER MINORC/O PATRICIA MILLER PARENT22 SUNSET BLVDDENVER CO 80203
CorrectFinancial or tax correspondence for a minor.

Quick reference

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Use c/o when...Use ATTN when...
Routing to a person through another personRouting to a person or role through a company
The recipient stays at someone else homeThe recipient works at that company
Sending to a hotel, dorm, or temporary staySending to a department inside a business
Estate mail addressed to an executorNever used for person-to-person routing

Special cases

The rule above covers most people. Here is what changes for the rest.

Why should mail to a deceased person's estate never be addressed directly to them?

Once someone has died, they can no longer legally receive or act on mail, and a piece addressed only to them has no one with clear authority to open it. Addressing it to the estate, care of the executor, gives the person with actual legal authority over the estate affairs a clean, unambiguous right to open and act on the correspondence. This matters most for anything financial or legal: tax notices, creditor letters, account statements. A bank or agency that receives a reply from someone other than the named executor may not accept it as valid.

What happens if mail arrives at a deceased person's old address without a c/o line at all?

It depends entirely on who currently receives mail at that address. If a surviving spouse or family member still lives there, it usually still gets opened and handled, informally. If the home has been sold or vacated, it can sit unclaimed, get returned, or in rare cases get opened by someone with no legal standing to act on it. Using the estate c/o format from the start avoids all of this ambiguity.

Does a hotel actually sort and hold personal mail for guests?

Some do, especially larger hotels with a front desk mail process, but plenty do not, particularly for a guest who has already checked out or a piece that arrives well before or after a stay. Confirm directly with the hotel before relying on this format for anything time-sensitive, and let the recipient know to ask at the front desk rather than assuming it will be delivered to their room automatically.

Key terms on this page

c/o
Care of. A routing instruction meaning the recipient does not live at the address being used and the mail is being handled by an intermediary on their behalf.
Intermediary
The person or place physically receiving c/o mail on someone else behalf, such as a host, a hotel front desk, or an estate executor.
Executor
The person with legal authority to manage a deceased person estate, including opening and responding to the deceased correspondence.

Check the address before you mail

Questions people ask

What does c/o mean on an envelope?
Care of. It tells the carrier and anyone else who might see the mail first that the person it is addressed to does not live at that address permanently, and that someone else there is accepting it on their behalf.
Where does c/o go on an envelope?
On the second line of the delivery address block: recipient name first, then C/O and the intermediary name, then the street address, then city, state and ZIP.
What is the difference between c/o and ATTN on an envelope?
C/O routes mail to a person through another person, typically at a home or temporary address. ATTN routes mail to a person or department through an organization, typically a business. Use c/o for a private residence or personal situation, ATTN for a company.
Can c/o be used for a package, not just a letter?
Yes, the same format works for packages. It is especially common for packages sent to someone at a workplace, a hotel, or a relative house while they are away from their usual address.
Does the intermediary need to sign for c/o mail?
Only if the mail itself requires a signature, such as certified mail. Ordinary c/o mail is delivered and left the same way any other mail would be, with no special signature requirement created by the c/o line itself.

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