Figuring out when mail will actually show up is half the battle. Below is a clean, up-to-date guide to USPS delivery speeds, what’s guaranteed (and what isn’t), how weekends/holidays affect timing, and the quickest way to estimate your own delivery window.
Are USPS delivery times guaranteed?
Most USPS delivery windows are estimates, not promises. The exception is Priority Mail Express, which offers an overnight–to–2-day money-back guarantee on many ZIP-to-ZIP lanes.
USPS delivery speeds by service (2025)
- First-Class Mail (letters & flats): 1–5 business days (estimate). Best for letters, postcards, and flats. Details
- USPS Ground Advantage (packages): 2–5 business days (estimate). Replaced Retail Ground, First-Class Package, and Parcel Select Ground; includes tracking and up to $100 insurance. Details
- Priority Mail (packages): typically 1–3 business days (estimate). Check your lane on the map. Delivery map
- Priority Mail Express: Overnight to 2-day, guaranteed in many areas. Details
Want your exact lane? Use the official USPS Service Standards Map to enter your origin ZIP and see expected timing to any destination.
Quick comparison
| Service | Typical Window | Guaranteed? | Tracking |
|---|---|---|---|
| First-Class Mail (letters & flats) | 1–5 business days | No | Optional (via extras) |
| USPS Ground Advantage | 2–5 business days | No | Yes |
| Priority Mail | 1–3 business days | No | Yes |
| Priority Mail Express | Overnight–2 days | Yes | Yes |
Do Saturdays count? What about holidays?
- Saturdays count as USPS business days for delivery calculations.
- Federal holidays don’t—there’s no regular delivery and those days are excluded from estimates. See the 2025 USPS holiday list.
Example: Shipped Wednesday with a 4-business-day estimate → Thu (1), Fri (2), Sat (3), Mon (4). If Monday is a USPS holiday, it lands Tuesday instead. (Saturday counts; holidays don’t.)
Blue collection boxes & “last pickup”
Transit time starts after your item makes the day’s posted collection time. Each blue box and Post Office™ counter has a label with that day’s final pickup—drop after that and it moves next business day. Check: latest collection time and collection box basics.
Why packages arrive late (and what you can do)
Even with published standards, weather, volume spikes, equipment outages, and mis-sorts can push an estimate late. For time-critical shipments, choose Priority Mail Express for a guarantee, and set up tracking alerts.
How to estimate your delivery date in 2 minutes
- Check your lane: Use the Service Standards Map (or the Priority Mail map).
- Confirm pickup timing: Make sure you’re before that location’s posted collection time.
- Adjust for weekends/holidays: Count Saturday, skip Sundays and federal holidays.
- Need a promise? Upgrade to Priority Mail Express.
Pricing in 2025 (keep this section evergreen)
Stamp and postage rates change. As of July 13, 2025, a Forever stamp is $0.78. Instead of hard-coding full price tables that go stale, link to USPS rate updates and service pages whenever you quote costs. See: USPS price update.
2025 holiday ship-by dates (quick guide)
For December 25 delivery in 2025, USPS suggests: Ground Advantage: Dec 16, First-Class Mail: Dec 17, Priority Mail: Dec 18, Priority Mail Express: Dec 20. Always ship earlier when possible and see the full list (Alaska, Hawaii, military, international) here: USPS holiday deadlines.
For businesses: set expectations clearly
- Show estimated delivery windows at checkout (service-specific) and offer a paid express upgrade for deadline-sensitive orders.
- Post a plain-English policy explaining estimates vs. guarantees and what to do if a parcel is late.
Don’t want to wait at home?
A Virtual Mailbox lets carriers deliver even when you’re not there. Your mail is received securely, you get notifications, and you can pick up or forward on your schedule—handy for travelers, remote teams, and anyone who can’t camp by the door. Explore plans & pricing or see our enterprise solutions.
