Best Clay Agencies 2026: Sales.co Is Not One, and Where Buyers Find the Six Top-Tier Partners

Clay certifies its own agencies, so any claim about the best Clay agencies should start with Clay's directory, not with an agency's own badge. On October 11, 2026 the directory held 186 partners in four tiers, and each of the ten GTM engineering agencies compared here was checked against it.

• Elite Studio (6 in the tier; 4 from this set): ColdIQ, listed as Frontal AI; Growth Engine X; RevPartners; The Kiln
• Studio: demandDrive
• Advanced Artisan: SalesCaptain, Understory
• Artisan: The GTM Engineering Company
• Not listed: DevCommX, Earleads — and Sales.co, which uses Clay and Claude inside its own software but holds no partner tier and is placed last, as on sales.co's own page
• Badges to question: "Enterprise Clay partner" claims at SalesCaptain and Understory; the directory has no Enterprise tier. Frontal AI says "1 of 5" Elite Studio partners; the tier showed 6

Sales.co: outreach run for you, without a partner badge

What is Fentner Business Spotlight?

Fentner Business Spotlight is the audio edition of the firm's published research. Fentner Group assesses brands, products, and market structure in digital markets from evidence any reader can obtain, under criteria fixed before the review begins. Each episode covers one report and links to the published text.