Nonprofit EIN API: Search by Name, Resolve an EIN, and Verify an Organization
If you are building a nonprofit directory, a grant platform, a CRM enrichment workflow, or an onboarding form, you eventually need to answer a simple question: which nonprofit does this name refer to?
Names are not reliable identifiers. Organizations can share similar names, use abbreviations, or operate in multiple states. The Employer Identification Number (EIN) gives your application a consistent way to identify the organization after you find it.
A simple nonprofit lookup workflow
The 501see API lets you start with the information you have and move toward a verified organization record:
- Search by name. Find likely matches using an organization name and, when available, a state or city.
- Resolve the EIN. Let the user confirm the right organization from the matching names and locations.
- Retrieve the organization. Use the EIN for future requests instead of repeating a fuzzy name search.
- Check the latest filing. Add current financial and filing context to your workflow when you need more than identity.
This works well for nonprofit onboarding, CRM enrichment, directory listings, grant platforms, and donation flows.
If you are doing this manually, How to Look Up a Nonprofit’s EIN covers several free lookup methods. If you are building a product or processing organizations repeatedly, an API gives you a repeatable workflow you can put inside your application.
Start free with verification
Developer Free is designed for verification-oriented use cases:
- Search for an organization by name.
- Look up an organization by EIN.
- Retrieve its latest filing.
That is enough to build a nonprofit lookup form, confirm organizations during onboarding, or enrich a record when a user submits a nonprofit name.
The API is not a replacement for the IRS’s official tax-exempt status search. For formal status verification, use the IRS Tax Exempt Organization Search. 501see is useful when you want to bring nonprofit identity and filing data into your own product and workflow.
When you need more than a lookup
The same workflow grows with your application.
Developer Basic adds the broader read API, including filing history and additional nonprofit, grant, officer, and foundation data. That is useful when your product needs to show trends, enrich records in depth, or support research workflows.
Developer Pro adds asynchronous exports for seeding a larger dataset and webhooks for keeping that data current after the initial load. In other words:
Find and verify → build on the data → export what you need → keep it fresh.
See the 501see developer documentation to create a developer account and start building.