Updated 2026-11-12
What the API DEF program is
API licenses DEF brands that meet ISO 22241 and agree to ongoing audits and testing. Licensed brands can show the API Diesel Exhaust Fluid Certification Mark on their packaging. Program details are on American Petroleum Institute, Diesel Exhaust Fluid Certification Program.
The license belongs to the brand
The license is held by the brand marketer, not by every company that resells or delivers the fluid. A distributor selling a licensed brand can say it sells an API-licensed brand. A new private label that has not been licensed cannot use the mark or call itself API certified, even if the fluid came from the same plant.
That is why BulkDEFNearMe does not describe itself as API certified. We quote licensed brands and name the brand on your quote so you can check it.
How to check a brand
- Find the brand name on the label or quote.
- Look for the API DEF certification mark on the package.
- Search the brand in API's public directory of licensed DEF products, linked from the program page above.
- Ask for a certificate of analysis or batch date if you buy in bulk.
Is API certified DEF required?
Engine makers specify DEF that meets ISO 22241. The API license is a widely used way to show a brand meets that standard and is audited. Many fleet buyers and OEM warranty programs look for it, so it is worth asking for.
What it costs a brand
API publishes its licensing fees. As of fees effective January 1, 2026, the program lists an application fee and annual renewal fee of $8,400 each, plus per-gallon royalties on licensed volume. Check API's site for current fees.
Questions
Is ISO 22241 the same as API certified?
No. ISO 22241 is the quality standard. API certification is a license that a brand meets it and is audited.
Does BulkDEFNearMe sell its own brand of DEF?
No. We quote established, API-licensed brands delivered through our fulfillment partners.