Everything your 501(c)(3) needs to know about USPS nonprofit mailing authorization — who qualifies, required documentation, 2026 rates, and how to apply.
If your organization has 501(c)(3) tax-exempt status, you may qualify for dramatically reduced USPS postage rates. Nonprofit Marketing Mail rates are among the lowest postage rates available — saving organizations thousands of dollars per year on fundraising appeals, newsletters, event invitations, and direct mail campaigns. Cornerstone has helped dozens of Hudson Valley nonprofits apply for and maintain their USPS authorization. Already have privileges? Learn how to update your nonprofit information with USPS Form 6015.
Mail Type / Sort Level
Commercial Rate
Nonprofit Rate
Savings
Letters — Carrier Route Saturation
$0.244
$0.155
37%
Letters — Automation 5-Digit
$0.372
$0.178
52%
Letters — Automation AADC
$0.407
$0.213
48%
Flats — Carrier Route Saturation
$0.290
$0.180
38%
Rates effective April 26, 2026 · Source: USPS Notice 123. Rates shown at no entry discount. DSCF/DDU entry discounts available. Actual rate depends on presort level and mailing weight.
Real Savings Example — 2026 Rates
A nonprofit sending 5,000 fundraising letters per quarter (20,000 annually) at 5-digit automation rates saves approximately $3,880 per year compared to commercial rates ($0.372 vs. $0.178 = $0.194/piece × 20,000). Over five years, that's nearly $19,400 returned to programs and services rather than spent on postage.
Who Qualifies for Nonprofit Rates?
USPS nonprofit mailing authorization is available to organizations that meet specific criteria in the USPS Domestic Mail Manual Part 703. Eligible organization types:
501(c)(3) charitable organizations
Religious organizations
Educational institutions
Scientific organizations
Veterans' organizations
Fraternal organizations
Qualified political committees
Volunteer fire departments
The Primary Purpose Requirement
USPS grants nonprofit authorization based on your organization's primary purpose — not simply its tax-exempt classification. A 501(c)(3) whose primary activities are commercial (a thrift store that generates most of its revenue from retail sales, for example) may be denied even with a valid IRS determination letter. USPS reviews financial statements, articles of incorporation, and representative mail samples at the time of application. If you're unsure whether your organization's revenue mix qualifies, contact us for a pre-application review.
PS Form 3624: The Application
PS Form 3624 is submitted to your local USPS Postmaster along with supporting documentation. The application is free and is available at any Post Office or at usps.com. Cornerstone reviews every application package before submission.
Required Documentation
Your application package must include: IRS determination letter confirming 501(c)(3) status, articles of incorporation or organizational charter, a description of your organization's primary activities, financial statements showing sources of income, and a sample of the mail type you intend to send at nonprofit rates.
Processing Timeline
USPS typically processes PS Form 3624 applications within 30–60 days. USPS may request additional documentation during review — this is the most common cause of delay. Cornerstone prepares and reviews your application package before submission and handles any USPS follow-up correspondence on your behalf.
Content Restrictions
Not all mail qualifies for nonprofit rates even after authorization. The content must further your organization's stated purpose. Pieces that don't qualify: cooperative mailings with for-profit entities, content primarily designed to sell goods or services, and travel advertising (even for nonprofit tours). Cornerstone reviews mail piece content before production.
How to Apply — Step by Step
1
Confirm your organization's eligibility
Verify your organization meets USPS nonprofit eligibility requirements. Eligible types include 501(c)(3) charitable organizations, religious organizations, educational institutions, scientific organizations, veterans' groups, fraternal organizations, and qualified political committees. Your organization's primary purpose must qualify — 501(c)(3) status alone is not sufficient if your primary activities are commercial.
2
Gather required documentation
Assemble your IRS determination letter confirming tax-exempt status, articles of incorporation or charter, a description of your organization's activities and purposes, financial statements showing sources of income, and a sample of the mail you plan to send at nonprofit rates.
3
Complete PS Form 3624
Fill out USPS PS Form 3624 (Application to Mail at Nonprofit USPS Marketing Mail Prices). The form is available at any Post Office or at usps.com. Cornerstone reviews completed applications before submission to minimize documentation errors and delays.
4
Submit to your local Postmaster
Submit the completed PS Form 3624 and all supporting documentation to the Postmaster at the post office where you plan to hold your mailing permit. In-person submission is recommended — staff can review your package on the spot and flag issues before you leave.
5
Wait for USPS review
USPS typically processes PS Form 3624 applications within 30–60 days. During this period USPS may request additional documentation. Cornerstone can respond to USPS inquiries on your behalf and track application status.
6
Receive authorization and set up your permit
Once approved, USPS issues a written authorization letter. You then set up a mailing permit and can begin mailing at nonprofit rates. Cornerstone handles permit setup and processes your first mailing as part of our full-service nonprofit mailing program.
How Cornerstone Helps Nonprofits
1
Pre-Application Review
We assess your organization's eligibility before you submit, identifying any documentation gaps or primary-purpose considerations that could cause delays.
2
Application Preparation
We prepare your PS Form 3624 package with all required supporting documents — IRS letter, articles, bylaws, financial statement, and mail sample.
3
List Processing
We process your donor/member list through CASS/DPV and NCOA to ensure deliverability and presort accuracy. Regular address change processing is the single biggest factor in mailing ROI.
4
Presort & Postage
We presort your mailing for maximum nonprofit postal discounts and handle all postage payment through your permit account.
5
Annual Maintenance
We help you maintain your authorization and ensure each mailing meets USPS nonprofit content standards every year.
Frequently Asked Questions
What is PS Form 3624?
PS Form 3624 — officially titled "Application to Mail at Nonprofit USPS Marketing Mail Prices" — is the USPS form your organization must submit to qualify for discounted nonprofit postage rates. You fill it out once, submit it with supporting documentation (IRS determination letter, articles of incorporation, and a description of your activities), and USPS grants permanent authorization after review. You don't reapply annually; the authorization stays in effect as long as your organization and its mailings continue to meet USPS requirements.
How much can our nonprofit actually save on postage?
Meaningful amounts — and more than most organizations realize. At current 2026 rates, nonprofit Marketing Mail letters at the 5-digit automation level cost $0.178 per piece versus $0.372 commercial — a 52% savings. A nonprofit sending 5,000 letters per quarter (20,000 annually) saves approximately $3,880 per year in postage alone at current rates. For saturation campaigns (carrier route, similar to EDDM), the nonprofit rate is $0.155 versus $0.244 commercial — a 37% savings. Organizations that have been mailing at commercial rates without nonprofit authorization are leaving thousands of dollars on the table annually.
Do we need our own mailing permit, or can we use Cornerstone's?
You need your own permit for nonprofit mailings — this is a USPS requirement, not a Cornerstone policy. USPS nonprofit authorization is granted to a specific organization and must be tied to that organization's own permit account. Unlike commercial bulk mailings (where Cornerstone can mail under our permit on your behalf), nonprofit mailings require the authorization to match the permit holder. We help you apply for both the nonprofit authorization and the permit simultaneously, and we manage the permit account on your behalf once it's established.
Can we send fundraising appeals and membership renewals at nonprofit rates?
Yes — fundraising solicitations, membership renewals, donor appeals, annual campaigns, and capital campaign letters all typically qualify, as long as the appeal furthers your organization's stated charitable purpose. What doesn't qualify: cooperative mailings that include for-profit content, pieces primarily designed to sell goods or services, travel advertising (even for nonprofit tours), and mailings whose content doesn't align with your approved organizational purpose. Cornerstone reviews mail piece content before production to confirm it meets USPS nonprofit content standards.
How long does the PS Form 3624 review process take?
USPS typically processes applications within 30–60 days. Complex cases — organizations with mixed commercial/nonprofit activities, or applicants whose documentation is incomplete — may take longer. The most common cause of delay is missing documentation, which is why Cornerstone reviews every application package before submission. Once approved, authorization is permanent. If USPS requests additional information, we handle that correspondence on your behalf.
Our organization is a 501(c)(3) — does that automatically qualify us?
501(c)(3) status is necessary but not sufficient. USPS evaluates your organization's primary purpose, not just its tax classification. A 501(c)(3) that primarily sells merchandise, operates a commercial bookstore, or provides paid commercial services may be denied even with a valid IRS determination letter. USPS looks at financial statements (what percentage of revenue comes from qualifying activities?), articles of incorporation, and representative mail samples. Organizations whose primary revenue is from qualifying charitable activities are almost always approved; organizations with significant commercial revenue should consult with us before applying.
Contact us for a free eligibility review. We'll confirm your organization qualifies, estimate your annual postage savings, and guide you through the complete PS Form 3624 process.
