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October 30, 2026
Flat Rate Overnight Shipping 2026: USPS vs FedEx One Rate vs UPS
2026 flat rate overnight shipping: a USPS Priority Mail Express Flat Rate Envelope costs $38.25 at the Post Office ($33.46 Commercial), FedEx One Rate Standard Overnight starts at $39.90 for an envelope, and UPS's only flat-rate next-day option is Simple Rate with Next Day Air Saver, from $35.45.
Quick answer: USPS has one flat price for each Priority Mail Express envelope to any U.S. address. FedEx One Rate is flat by package and by zone band (Local, Regional, National) and includes fuel and residential charges. UPS has no flat rate for Next Day Air or its Express Box, but UPS Simple Rate prices Next Day Air Saver by box size from $35.45 to $96.70 anywhere in the 48 contiguous states, with no residential or fuel surcharge.
Sources: USPS Notice 123 (effective October 4, 2026); FedEx Service Guide 2026 (updated September 11, 2026) and FedEx One Rate page (checked October 30, 2026); UPS 2026 Daily Rates (updated September 7, 2026).
USPS Priority Mail Express Flat Rate Envelopes
| Envelope | Size | Retail (Post Office) | Commercial (online) |
|---|---|---|---|
| Flat Rate Envelope | 12-1/2" x 9-1/2" | $38.25 | $33.46 |
| Legal Flat Rate Envelope | 15" x 9-1/2" | $38.55 | $33.78 |
| Padded Flat Rate Envelope | 12-1/2" x 9-1/2" | $39.25 | $34.05 |
- Same price to any U.S. address for anything that fits, up to 70 lbs, per USPS. The flaps must close within the normal folds.
- Envelopes only. The Flat Rate Boxes in Notice 123 are Priority Mail, the slower service.
- Delivery is 1–3 days by 6 PM with a money-back guarantee and up to $100 of insurance with most shipments.
- Holiday pricing. USPS added $2.35 to the Priority Mail Express Flat Rate Envelopes in its temporary holiday price change, in place until 12 a.m. CT on January 17, 2027.
Weight-based Priority Mail Express prices are in USPS Overnight Shipping Cost 2026.
FedEx One Rate Overnight Prices
FedEx One Rate is a flat price for FedEx packaging that "includes any applicable residential surcharges, delivery area surcharges, and fuel surcharge." The price depends on the package type, the service and the zone band: Local (zone 2), Regional (zones 3–4) or National (zones 5–8, plus Alaska and Hawaii shipments).
FedEx One Rate Standard Overnight (next day by 5 p.m.)
The envelope, pak and the Small, Medium, Large and Extra Large boxes also come in other sizes; dimensions are from the FedEx One Rate page.
| Packaging | Dimensions | Local | Regional | National |
|---|---|---|---|---|
| FedEx Envelope | 9-1/2" x 12-1/2" | $39.90 | $41.55 | $55.60 |
| FedEx Extra Small Box | 7-1/4" x 2-1/2" x 4-11/16" | $43.25 | $50.30 | $66.30 |
| FedEx Pak | 10-1/4" x 12-3/4" | $50.95 | $70.60 | $91.30 |
| FedEx Small Box | 10-7/8" x 1-1/2" x 12-3/8" | $54.75 | $77.05 | $101.75 |
| FedEx Medium Box | 11-1/2" x 2-3/8" x 13-1/4" | $59.40 | $81.30 | $105.80 |
| FedEx Large Box | 12-3/8" x 3" x 17-1/2" | $71.65 | $97.90 | $146.70 |
| FedEx Extra Large Box | 11-7/8" x 10-3/4" x 11" | $81.30 | $132.65 | $203.85 |
FedEx One Rate Priority Overnight (next day by 10:30 a.m.)
| Packaging | Local | Regional | National |
|---|---|---|---|
| FedEx Envelope | $49.50 | $66.05 | $81.95 |
| FedEx Extra Small Box | $52.75 | $75.95 | $97.10 |
| FedEx Pak | $60.35 | $99.05 | $132.40 |
| FedEx Small Box | $61.45 | $107.85 | $148.20 |
| FedEx Medium Box | $70.95 | $122.90 | $167.65 |
| FedEx Large Box | $79.00 | $139.55 | $193.05 |
| FedEx Extra Large Box | $93.95 | $182.60 | $268.05 |
The FedEx Tube is priced the same as the Extra Large Box. First Overnight (8 or 8:30 a.m.) is also available, from $103.50 for a Local envelope to $322.05 for a National Extra Large Box.
Note: these Standard Overnight prices are from the Service Guide, which marks them effective April 20, 2026. FedEx's One Rate web page (checked October 30, 2026) shows lower Standard Overnight prices "effective June 26, 2026", such as $31.20 for a Local envelope and $37.90 for a Regional or National envelope. Priority and First Overnight prices match in both, and FedEx's separate One Rate pricing PDF (effective September 11, 2026) matches the Service Guide. Confirm at checkout.
- Weight limits: FedEx envelopes must weigh 10 lbs. or less; paks, boxes and tubes 50 lbs. or less.
- No overstuffing: an envelope over 3 inches thick, or a pak over 5 inches, is rated as a box.
- No account discounts. Saturday delivery, signature options, extra declared value and address corrections still cost extra. No dry ice.
Does UPS Have Flat Rate Overnight Shipping?
Not for UPS Next Day Air or Next Day Air Early. The 2026 UPS daily rates guide has no flat price for the UPS Express Box; outside Simple Rate it is rated by weight and zone. The UPS Express Envelope gets a "Letter" rate for documents up to 8 ounces, but it still varies by zone: $37.30 to $71.47 for Next Day Air and $36.00 to $66.89 for Next Day Air Saver, before fuel. See UPS Next Day Air Letter Cost 2026.
UPS Simple Rate does include next-day service. Its four options are Next Day Air Saver, 2nd Day Air, 3 Day Select and Ground. The price depends on box size in cubic inches (length x width x height), not weight or zone.
| Simple Rate size | Cubic inches | Example box | Next Day Air Saver | 2nd Day Air |
|---|---|---|---|---|
| Extra Small | 1–100 | 8 x 6 x 2 | $35.45 | $24.55 |
| Small | 101–250 | 8 x 6 x 5 | $45.00 | $29.25 |
| Medium | 251–650 | 12 x 9 x 6 | $50.45 | $37.50 |
| Large | 651–1,050 | 10 x 10 x 10 | $74.50 | $65.60 |
| Extra Large | 1,051–1,728 | 12 x 12 x 12 | $96.70 | $85.45 |
- Prices are between the 48 contiguous states. Simple Rate Next Day Air Saver isn't available to Alaska or Hawaii.
- No Residential, Delivery Area or fuel surcharges. Other value-added fees still apply.
- Limits: 50 pounds and 1,728 cubic inches. Use your own box or poly mailer, or UPS Express packaging for Next Day Air Saver and 2nd Day Air.
- Not available for hazardous materials, third-party billing or freight collect. No UPS account is needed.
Flat Rate Overnight Options Compared
| Option | Price (2026) | Fuel and residential | Delivery |
|---|---|---|---|
| USPS Priority Mail Express Flat Rate Envelope | $38.25–$39.25 retail; $33.46–$34.05 Commercial | No separate charge in Notice 123 | 1–3 days by 6 PM |
| FedEx One Rate Standard Overnight | $39.90–$55.60 envelope; $43.25–$203.85 boxes | Included | Next day by 5 p.m. (8 p.m. to residences) |
| FedEx One Rate Priority Overnight | $49.50–$81.95 envelope; $52.75–$268.05 boxes | Included | Next day by 10:30 a.m. |
| UPS Simple Rate, Next Day Air Saver | $35.45–$96.70 by box size | Not charged | End of next business day |
| UPS Next Day Air Saver Letter (not flat) | $36.00–$66.89 by zone | Fuel and residential added | End of next business day |
When Flat Rate Beats Weight-Based Pricing
Flat rate wins when a package is heavy for its size, going far, or going to a home:
- UPS, 5 lb in a 12 x 9 x 6 box to a home in zone 8. Next Day Air Saver is $145.06, plus $49.68 of fuel at the 34.25% UPS air rate for the week of November 2, 2026 and the $7.00 residential surcharge: about $201.74. The box is 648 cubic inches, a Simple Rate Medium, so the same service is $50.45.
- FedEx, 5 lb to a home in zone 8. Standard Overnight is $141.30 plus the $6.95 residential charge, $148.25 before fuel. In a FedEx Medium Box, One Rate Standard Overnight in the National band is $105.80 with fuel and residential included.
- USPS, 3 lb of documents to zone 8. Priority Mail Express retail is $84.50 by weight. If they fit a Flat Rate Envelope, it is $38.25.
When weight-based can win: light packages over short distances, and shippers with strong contract discounts, which One Rate ignores. A 1 lb FedEx Standard Overnight package in zone 2 is $40.82 at list before fuel, against $54.75 for a One Rate Small Box. Price both ways at your own rates. Weight-based next-day rates are in our next-day shipping cost guide.
2027 update: UPS daily rates rise an average net 5.9% on December 21, 2026 (UPS 2027 rate update), and UPS's 2027 daily rates preview lists Simple Rate Next Day Air Saver at $37.75 to $102.40 between the 48 contiguous states. FedEx list rates rise an average 5.9% on January 4, 2027 (FedEx rate changes); check fedex.com for 2027 One Rate prices. USPS's current prices, including the $2.35 holiday increase on Priority Mail Express Flat Rate Envelopes, run until January 17, 2027.
Frequently Asked Questions
Does UPS have flat rate overnight shipping?
Only through UPS Simple Rate, which prices Next Day Air Saver by box size: $35.45 to $96.70 in 2026 within the 48 contiguous states, with no residential or fuel surcharge. UPS Next Day Air is priced by weight and zone.
How much is a USPS overnight flat rate envelope?
A Priority Mail Express Flat Rate Envelope is $38.25 at the Post Office or $33.46 Commercial. Legal is $38.55 or $33.78; Padded is $39.25 or $34.05. Delivery is 1–3 days.
How much is FedEx One Rate overnight?
Per the 2026 FedEx Service Guide, Standard Overnight is $39.90 to $55.60 for an envelope and Priority Overnight $49.50 to $81.95, including fuel and residential charges. FedEx's One Rate web page shows lower Standard Overnight prices.
Is the UPS Express Box flat rate?
No. Outside UPS Simple Rate, a UPS Express Box is charged by weight and zone.
What is the weight limit for flat rate overnight shipping?
USPS Priority Mail Express Flat Rate Envelopes: up to 70 lbs if the contents fit. FedEx One Rate: 10 lbs. for envelopes and 50 lbs. for paks, boxes and tubes. UPS Simple Rate: 50 pounds and 1,728 cubic inches.
Does flat rate shipping include residential and fuel surcharges?
FedEx One Rate includes them, and UPS Simple Rate does not charge them. USPS Notice 123 lists no separate fuel or residential charge.
Related Reading
- USPS Overnight Shipping Cost 2026: Priority Mail Express Prices
- FedEx Overnight Envelope Cost 2026: Standard, Priority & First Rates
- UPS Next Day Air Letter Cost 2026: Overnight Envelope Rates by Zone
- Cheapest Overnight Shipping 2026: USPS vs UPS vs FedEx Rates Compared
- FedEx First vs Priority vs Standard Overnight: Times and Costs (2026)
- How to Overnight a Check or Documents: 2026 Costs and Carrier Rules
Get a free shipping invoice audit
We check UPS and FedEx invoices line by line for surcharges that should not have been billed and for packages that would have cost less under a different rate option. Request a free invoice audit to see what you can recover.
This article is for informational purposes only. Carrier rates, surcharges, and policies change frequently — always verify current terms directly with the carrier for your specific situation. Have questions? Reach out to us — we're happy to help.
Meet the Author
paul@darrigoconsulting.com
I’m Paul D’Arrigo. I’ve spent my career building, fixing, and scaling operations across eCommerce, fulfillment, logistics, and SaaS businesses, from early-stage companies to multi-million-dollar operators. I’ve been on both sides of growth: as a founder, an operator, and a fractional COO brought in when things get complex and execution starts to break
