USPS Lost Mail: Search, Claims, Theft

The short answer

USPS treats mail as missing when it hasn’t arrived by its expected delivery date. Check USPS Tracking first if the item has a tracking number; then, starting 7 days after the mailing date, submit a Missing Mail search request at MissingMail.USPS.com (the tool accepts requests up to 365 days after mailing). If the item was insured, file a claim no later than 60 days after the mailing date, and report suspected theft to the U.S. Postal Inspection Service at 1-877-876-2455.

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When does USPS consider mail lost?

USPS defines missing mail as mail that hasn’t been delivered by the expected delivery date, whether it’s undelivered, lost, or simply late. That means the first question isn’t “Is it lost?” but “Is it actually overdue?” USPS’s own chart of delivery standards gives First-Class Mail 1–5 business days, Priority Mail 2–3 business days to most of the country, and USPS Ground Advantage 2–5 business days. None of those standards is guaranteed; only Priority Mail Express carries a guarantee, at 1–3 calendar days.

Once something has been lost, late, or missing for 7 days or more, USPS says you can submit a Missing Mail search request, file a claim if the item was insured, or visit your local Post Office for help. A letter that’s one or two business days past the standard is usually still in transit. For what to do while you wait, see our guide on how long a letter takes to arrive.

What should you check before reporting lost mail?

USPS asks you to start with the information you already have. A few quick checks often solve the mystery before you file anything.

Check USPS Tracking if the item has a tracking number. Priority Mail, Priority Mail Express, and USPS Ground Advantage include tracking; a First-Class letter is trackable only if you added a service such as USPS Tracking, Signature Confirmation, or Certified Mail.
If tracking shows “Delivered” but you can’t find the item, look in a parcel locker (a key in your box means a locker holds your item) and ask your building office. USPS says that if it’s been more than one postal business day since the delivered scan, you can use the Email Us page on usps.com to send a service request to your local Post Office for eligible items.
If you use Informed Delivery, check the daily preview of incoming mail. USPS notes that a previewed item may sometimes be delayed in reaching you.
Confirm the address with the other person. Mail that can’t be delivered as addressed is often returned to the sender rather than lost; our article on returned-to-sender mail explains why.
If mail is late, USPS suggests noting the delivery date on the envelope and taking it to your local Post Office, since marks on the envelope can show what caused a delay.

How do you file a USPS Missing Mail search?

The Missing Mail search is USPS’s main tool for lost mail, and either the sender or the recipient can start one. The application lets you submit a request as early as 7 days after the original mailing date and as late as 365 days after it; USPS strongly suggests filing as soon as you can within that window. Customer Care representatives can’t file the request for you, so you’ll need to do it yourself.

Go to MissingMail.USPS.com, sign in or register, and complete the form. You can save a draft, but drafts expire after 7 days. Each missing piece needs its own request: one request can list several items packed inside a single envelope or box, but not several separate mailpieces.

The sender’s and recipient’s mailing addresses.
The mailing date, taken from your receipt if you have one.
Any tracking number (USPS highly recommends including it if available).
The size, type, and color of the envelope or box, such as a 12 × 10 brown box covered in stickers.
A detailed description of each item inside, including title, color, size, brand, make, or model.
Photos of the contents, if you have them.

What happens after you submit a Missing Mail search?

USPS sends a confirmation email when it receives your request, then periodic updates to the contact email you gave on the form. You can also check every request on the Missing Mail Search History page. The request is matched against items in USPS’s inventory, and its status will show as Accepted, Mailpiece Found, Expired, Saved as Draft, Rejected (for example, a duplicate), or Canceled.

If the search finds your item, USPS rewraps it and mails it to the address you entered on the form, and the status changes to “Mailpiece Found.” If nothing matches, the search keeps running until it expires, and you’ll get an email saying the item couldn’t be found. USPS is candid that a search doesn’t guarantee success, and some items can’t be searched for or returned for safety reasons, including hazardous materials, live ammunition, prescription and over-the-counter drugs, and perishable food.

USPS FAQ: Missing Mail – The Basics

How long do you have to report lost mail?

Each step has its own clock, and most are counted from the mailing date, not the date you noticed the problem. Keep your receipt: it’s how you prove that date.

USPS lost-mail timelines (counted from the mailing date unless noted)
Step	Earliest	Latest
Missing Mail search request	7 days after mailing	365 days after mailing
Service request after a “Delivered” scan you can’t find	More than 1 postal business day after the scan	Not stated by USPS
Insurance claim: damaged or missing contents	Immediately	60 days after mailing
Insurance claim: lost Priority Mail Express	7 days after mailing	60 days after mailing
Insurance claim: lost Priority Mail, USPS Ground Advantage, Insured Mail, COD, or Registered Mail	15 days after mailing	60 days after mailing
Missing Mail search draft	—	Expires 7 days after you save it

USPS: File a USPS Claim (Domestic)

Can you file a USPS claim for lost mail?

Only if the item was insured. A search request asks USPS to find your mail; an indemnity claim asks USPS to pay for it. USPS lists eligible items as Priority Mail Express and other insured mail, Collect on Delivery (COD) items, and Registered Mail items with insurance. Either the sender or the recipient may file, but the person filing must have the original mailing receipt, and each claim must include proof of insurance and value.

Some services include insurance in the price. Priority Mail Express and Priority Mail include up to $100, and so does USPS Ground Advantage, as long as the shipment has an applicable USPS Tracking barcode. For more coverage, USPS sells Insured Mail up to $5,000; at current prices (Notice 123, effective October 4, 2026), insurance for an item valued at $0.01–$50 costs $2.80. An ordinary First-Class letter with a stamp carries no insurance, so there’s no claim to file if it disappears; the search request is your only USPS remedy.

Timing depends on what happened. If an item arrives damaged or missing contents, you may file right away but no later than 60 days after the mailing date. If it never arrives, wait until the earliest filing date for the service you used (see the table above) and file before the 60-day deadline. If you paid for a money-back guarantee, such as Priority Mail Express, you may be able to request a refund instead.

What if USPS lost your Certified Mail?

Certified Mail ($5.55 plus postage at current prices) gives the sender a mailing receipt and a USPS delivery record, but the Domestic Mail Manual says it is dispatched and handled in transit as ordinary mail. Except for Priority Mail pieces with included insurance, no insurance comes with Certified Mail, so a lost certified letter usually can’t be the subject of an indemnity claim.

What Certified Mail does give you is evidence. Enter the article number from your receipt at usps.com or call 1-800-222-1811 to see the delivery status, and USPS can email a proof of delivery letter that includes a signature when one is available. If tracking stalls, file a Missing Mail search after 7 days and include the article number. If the letter was meeting a deadline, keep the receipt as evidence of when you mailed it and send a replacement; our Certified Mail explainer covers what the receipt and delivery record show.

Is it lost mail or mail theft?

Lost mail is a service problem; stolen mail is a federal crime, and it goes to a different agency. If you suspect theft, such as a pried-open mailbox, several neighbors missing mail, or a mailed check cashed by someone else, report it to the U.S. Postal Inspection Service online or at 1-877-876-2455, and call 911 for a crime in progress. The Inspection Service itself points customers with delivery delays or service issues back to the USPS help page.

If the missing item was a check, contact your bank as well; our guide to mailing a check covers stop-payment steps.

What if you lost your mailbox key?

Who replaces a lost mailbox key depends on who owns the box. USPS doesn’t sell or provide personal mailboxes, and it neither opens a locked private box nor accepts a key to one. For cluster mailboxes or apartment boxes that USPS owns and maintains, contact your local Post Office. USPS keeps no duplicate keys, so if every key is lost it installs a new lock and issues new keys at your expense; there’s no set fee, and the charge is based on local costs.

For every other mailbox, including boxes owned by an apartment or condo complex, ask the building owner or manager. They’re responsible for the boxes and locks and may keep a spare key; USPS says it can’t help you get into privately owned mailboxes.

For a PO Box, a worn or broken key is replaced free when you return it to the Post Office where the box is located. Otherwise, extra or replacement keys cost $14.00 each after the first two, plus a refundable $6.00 deposit per key, and a lock change costs $30.00 (Notice 123, effective October 4, 2026).

What should the sender and recipient each do?

Both sides can act, but they hold different pieces of evidence. Coordinate so you file one Missing Mail search with complete details rather than two thin ones, because USPS may reject duplicates.

Sender: find the receipt, the mailing date, and any tracking or Certified Mail number; check tracking; and file the Missing Mail search or insurance claim, since the person filing a claim needs the original receipt.
Recipient: confirm with the sender that the item is overdue, check parcel lockers, the building office, and Informed Delivery, and ask your local Post Office about a missing delivery.
Either side: report suspected theft to the Postal Inspection Service, and decide early whether to resend a time-sensitive document rather than wait for a search that may not succeed.

How to prove a letter was mailed

Can you resend a lost letter without going to the Post Office?

If the lost item was a letter you can reprint, resending it is often faster than waiting on a search. IRIS Postal Forms, an independent print-and-mail service that isn’t affiliated with USPS, prints the US Letter-size PDF you upload and mails it by USPS First-Class Mail to a US address, from $3.20 for a one-page black-and-white letter. You review the document, addresses, options, and total before paying.

Add Certified Mail for $6.95 if you want tracking, which appears on your IRIS order page; regular IRIS letters don’t include tracking. IRIS can’t mail packages or physical items such as checks or originals, doesn’t offer insurance or Registered Mail, and doesn’t guarantee delivery dates, so the USPS steps above still apply if a piece goes missing.

Sources & further reading

Product details checked against the IRIS API contract when this article was published. Platform references can change; consult the linked documentation when implementing.

Published by IRIS Postal Forms, operated by Great Lakes Computing Office LLC. Send a correction.

Put it into practice

Need to send the letter again?

If a letter went missing and you need to resend it, IRIS prints the US Letter-size PDF you upload and mails it by USPS First-Class Mail, from $3.20 for one black-and-white page, with no stamps or envelope needed. Add Certified Mail for $6.95 to get tracking on your order page. IRIS doesn’t guarantee delivery dates, and order status isn’t proof of delivery.

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