BuyHolidayStamps.com is a secondary source. The facts that matter most — postage rates, size and weight limits, addressing standards, service rules, and holiday schedules — come from the United States Postal Service itself. This page lists the official sources our guides rely on, so you can verify any statement at its origin.
Primary Source: USPS
USPS Official Website
usps.com — the Postal Service’s main site. We use its service pages for First-Class Mail and other mail classes, retail and holiday information, Post Office locations and hours, and the Postal Store, where USPS sells stamps and supplies directly.
USPS Newsroom
about.usps.com/newsroom — USPS news releases, including annual holiday mailing announcements, recommended holiday mailing dates, price change notices, and new stamp issue announcements. When a guide mentions a USPS holiday deadline or a rate change, this is usually where it was announced.
Postal Explorer
pe.usps.com — the Postal Explorer library of USPS manuals and standards, including the Domestic Mail Manual. This is the authoritative reference for addressing standards, mail preparation, and size and weight rules cited in our USPS Mailing Rules guides.
USPS Postal Store
store.usps.com — the official USPS online store for stamps and mailing supplies, referenced in our Stamp Buying Guide as the direct source for current stamp issues.
Supporting Official Sources
Federal Holidays (OPM)
opm.gov — Federal Holidays — the U.S. Office of Personnel Management’s list of federal holidays, used to keep the Holiday Mailing Calendar aligned with the official holiday schedule that USPS observes.
How We Use These Sources
- Each article’s facts are checked against the specific official page that supports them, at the time the article is written or updated.
- When USPS publishes a change — a new price, a new recommended mailing date, a revised rule — affected pages are reviewed and updated under our Content Updates Policy.
- If an official source and any page on this site ever differ, the official source is correct and we want to know: report it via Contact Us so the page can be fixed.
- Links to retailer websites in buying-related content are provided for reader convenience only. Retailers are not sources for USPS rules, and their pages are never used to establish rates, deadlines, or requirements.
A Note on Dates and Prices
Postage prices change, and holiday mailing recommendations are issued seasonally. A page on this site reflects the official information available when it was last verified, as described in our Editorial Policy. For a purchase or mailing decision that depends on today’s exact rate or date, confirm it on usps.com before you buy postage or send.