A seized USPS package sits in a unique legal position, and which way it breaks depends on what was inside and whether it came from abroad. Cash taken from domestic mail brings a Fourth Amendment protection that no private carrier package enjoys — a genuine advantage. Merchandise stopped in inbound international mail, by contrast, is a customs seizure much like any other import. The Postal Service touches both worlds, so a “USPS seizure” can mean quite different things.
This page covers both tracks — the mail-privacy protections that apply to domestic cash, and the customs process that governs seized international mail parcels.
Two Tracks for Seized Mail
Cash in domestic mail
- Currency intercepted in the U.S. mail stream
- Civil forfeiture as suspected proceeds (CAFRA)
- Sealed mail carries Fourth Amendment protection
- Opening it generally requires a warrant
- The search itself may be challengeable
Goods in international mail
- Inbound international mail parcels inspected by CBP
- Counterfeit or infringing goods
- Undervaluation, or failure to declare
- Inadmissible / contrary-to-law merchandise
- Customs seizure process, often non-CAFRA
The Cash Track: The Fourth Amendment Advantage
Sealed letters and packages in the U.S. Mail have long been protected against unreasonable search. As a general rule, law enforcement cannot open sealed domestic mail without a warrant supported by probable cause — a meaningfully higher bar than the consent-based inspections a private carrier can facilitate for a FedEx or UPS parcel.
The warrant requirement is a challenge point private carriers don’t offer
Because opening sealed mail generally requires a warrant, every USPS cash seizure raises a question a FedEx or UPS case often does not: was the search lawful? If investigators opened the package without a valid warrant, or on a warrant resting on thin or stale information, the search can be contested — and if it falls, the forfeiture can fall with it.
That is on top of the ordinary defense: a documented, legitimate source of funds. The combination of a search challenge and a solid source-of-funds record is what makes strong USPS cash cases genuinely winnable.
The protection has limits. Investigators can generally examine a package’s exterior, run a drug dog over the outside, briefly detain a parcel, and watch addresses of interest — all without a warrant. The U.S. Postal Inspection Service runs its own interdiction program alongside DEA, IRS Criminal Investigation, and local task forces, profiling parcels and then using a sniff or a short detention to build probable cause. Two pressure points recur: whether a package was detained longer than justified before a warrant issued, and whether the warrant affidavit truly established probable cause. Both are litigable. Once cash is seized, the case proceeds as a CAFRA civil forfeiture — 60-day notice, 35-day claim window, 90-day complaint deadline — the framework detailed in our cash seized in transit overview and domestic cash seizure practice.
A controlled delivery is an investigation, not a delivery
Sometimes investigators do not simply seize a parcel — they deliver it under surveillance to see who accepts it. If you take a package and are immediately questioned, you are the subject of an investigation. You are not required to answer, and explaining on the spot, even to assert innocence, can supply evidence the government did not have. Decline the interview and get counsel first.
The Goods Track: International Mail Is a Customs Seizure
Inbound international mail is a different animal. Parcels entering the country through the international mail system are subject to CBP inspection, and merchandise found to be counterfeit, undervalued, undeclared, or otherwise inadmissible can be detained and seized — a customs seizure, not a domestic forfeiture, and one where the heightened protection for sealed domestic mail does not carry the same force at the border. The grounds and the pages that address them are the same as for any import seizure.
| Ground | Where to turn |
|---|---|
| Counterfeit / IP goods | See counterfeit import seizures and penalties |
| Undervaluation / misclassification | See customs valuation |
| Failure to declare | See failure to declare under 19 USC 1497 |
| Goods held, not yet seized | See customs detention of merchandise |
| General seizure defense | See non-CAFRA customs seizure defense |
As with other customs merchandise seizures, these are often non-CAFRA, arriving with a customs seizure notice and an election-of-proceedings decision rather than a CAFRA claim. The right response depends on the ground for seizure and your goals for the goods.
What to Do When the Mail Brings a Seizure Notice
Identify the track. If it is domestic cash, preserve the possible Fourth Amendment challenge by getting the search facts reviewed early, and assemble your source-of-funds documentation. If it is an international mail parcel of goods, treat it as the customs seizure it is and gather your import and valuation records. In both cases, calendar the response deadline from the notice date, and do not talk to the seizing agency without counsel — whether the case is about cash or merchandise, statements become part of the record.
Because a USPS seizure can turn on mail-privacy law, on customs law, or on both, a customs and international trade lawyer can evaluate whether a mail search was lawful, handle the customs process for seized international parcels, and meet the deadline either way. If your shipment moved through a private carrier instead, see our pages on FedEx, UPS, and DHL seizures, or start with our currency seizure practice overview.
Frequently Asked Questions
Can the government open my mail to look for cash or goods?
For sealed domestic mail, generally not without a warrant — investigators can examine the exterior, use a drug dog on the outside, and briefly detain a parcel, but opening it usually requires a warrant. Inbound international mail is different: it is subject to CBP inspection at the border, where the customs authority to examine imports applies.
Is a USPS cash seizure easier to fight than a FedEx or UPS one?
In one key respect, yes. Because opening sealed mail generally requires a warrant, a USPS cash seizure can be challenged on the lawfulness of the search itself — a line of attack private-carrier consent searches often do not present. If the search was unlawful, the forfeiture can fail. Strong source-of-funds documentation remains essential.
Customs seized a package I received through international mail. What now?
That is a customs seizure, commonly for counterfeit, undervalued, undeclared, or inadmissible goods, and it is frequently non-CAFRA — meaning a customs seizure notice and an election-of-proceedings decision. Note the deadline on the notice and respond through the customs process; the ground for seizure shapes the defense.
Cash or goods seized from the mail?
Domestic mail may give you a Fourth Amendment challenge; international mail is a customs matter. A customs attorney can pursue the right one within your deadline.