How do you ship liquids by USPS?
Close each bottle with a screw cap of at least 1-1/2 turns (or similar), triple-package any glass, plastic or other breakable container over 4 fl oz, mark the box as liquid, and put up arrows on two opposite sides if it holds more than 4 oz.
A parcel with more than 24 oz of liquid in glass, or 1 gallon or more in metal or plastic, also pays the $4.50 nonstandard fee by Ground Advantage or Priority Mail. Flammable liquids have their own limits (perfume, nail polish and aerosols).
Rates verified on
Postage in the examples is from Notice 123 effective Oct 4, 2026, which includes USPS's temporary holiday prices for Ground Advantage and Priority Mail until 12 a.m. CT Jan 17, 2027. The fees quoted here are the same as in the July 12, 2026 edition, before the holiday prices began.
The rule, in USPS's words
“Mailers must mark the outer container of a mailpiece containing liquid to indicate the nature of the contents (i.e. liquid), and include orientation arrows in accordance with Publication 52, section 223.”
“Use screw-on caps with a minimum of one and one-half turns, soldering, clips, or similar means to close primary containers containing liquids.”
“Breakable containers including, but not limited to, those made of glass, plastic, porcelain, and earthenware, and metal containers with pull-tabs (pop-tops) or friction-top closures, having a capacity of more than 4 fluid ounces must be triple-packaged”
“Packages containing liquids or spillable materials exceeding 4 ounces must display orientation arrows.”
“A parcel containing more than 24 ounces of liquid in glass containers, or 1 gallon or more of liquid in metal or plastic containers (see 601.3.4).”
What it costs, with examples
| Shipment | Triple packaging | Up arrows | Nonstandard fee |
|---|---|---|---|
| One 3 oz glass bottle of lotion | not required (4 fl oz or less) | not required | none |
| One 8 oz glass bottle | required | required | none |
| Three 8 oz glass bottles (24 oz) | required | required | none (not more than 24 oz) |
| Four 8 oz glass bottles (32 oz) | required | required | $4.50 |
| Two 16 oz plastic bottles (32 oz) | required | required | none (under 1 gallon in plastic) |
| One 1 gallon plastic jug | required | required | $4.50 |
| Label | Postage | Fee | Total |
|---|---|---|---|
| Ground Advantage, online | $12.12 | $4.50 | $16.62 |
| The same bottles split three and one, two 2 lb boxes | $21.00 | none | $21.00 |
Edge cases
- Triple packaging means: absorbent cushioning that can soak up all the liquid, a sealed leakproof secondary container (a watertight can or plastic bag), and a strong sealed outer box (DMM 601.3.4c).
- Alternative: containers certified to ISTA Test Procedure 3A can replace triple packaging if you can show the test results (DMM 601.3.4d).
- Push-down lids: friction-top closures aren't allowed for primary containers except under the triple-packaging rule.
- Steel pails and drums with positive closures can go without extra packaging (DMM 601.3.4b).
- Arrows: two underlined arrows showing the upright position, on two opposite sides, with each bottle's closure upright (Publication 52, 223).
- Splitting can cost more: in the example, two boxes cost $4.38 more than one box with the fee, so check before you split.
What to do
- Tape or band caps, bag each bottle, add absorbent pads, and box it with cushioning.
- Write "liquid" on the box and draw up arrows on two opposite sides.
- Price one box with the $4.50 fee against two smaller boxes before splitting.
Questions
Do I have to triple package a plastic bottle?
Yes, if it holds more than 4 fl oz: the DMM lists plastic among the breakable containers that must be triple-packaged (DMM 601.3.4c).
Does USPS charge extra for liquids?
Only over the limits: $4.50 for more than 24 oz in glass or 1 gallon or more in metal or plastic (Notice 123; DMM 201.7.6.2).
Sources
Rates verified on from each official page below.
- USPS Notice 123, Price List (effective Oct 4, 2026)
- USPS Domestic Mail Manual 201: physical standards for commercial mail (flats, parcels, nonstandard parcels)
- USPS Domestic Mail Manual 601: mailability, packaging and USPS-produced packaging
- USPS Publication 52, 223: orientation markings for packages containing liquids
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