The short answer
Mostly not yet, for a typical business under 50 employees, and Middesksays as much about itself: it's built to sit behind a signup or vendor-onboarding flow via API, not to be a dashboard you log into. There's no self-serve signup and no published price, you negotiate a per-verification rate (reported around $2–$5 a check at real volume) through a sales process. If your version of “onboarding a vendor” is adding a new contractor to QuickBooks a few times a quarter, you don't have the volume to justify that sales cycle, and you probably don't have engineers sitting free to integrate it either.
When it actually pencils out
The math flips once your business is regularly paying a rotating set of companies rather than people, staffing and recruiting firms, marketplaces, agencies that bring on new subcontractor entities every month, property managers paying a changing list of vendors. That's the exact shape of risk Middesk is built for: someone sets up a shell company as a “vendor” and routes payments to themselves, and Middesk catches it before the first check goes out by checking the entity against real registry data instead of trusting whatever name was typed into a form.
What Middesk actually checks
50 states + IRS
Middesk connects directly to every state Secretary of State registry plus IRS EIN records, so a fake or dissolved entity shows up as exactly that, not as a plausible-looking form submission.
What it costs in practice
Budget for two separate line items: core verification (reported $2–$5 per check, volume-tiered and negotiated) and ongoing monitoring, which is priced separately and is what catches a previously-clean vendor going bad later, a registration lapsing, a beneficial owner changing, a name showing up on a sanctions list. Neither number is public, so budget a real sales conversation before you know what you'd actually pay.
The honest alternative at low volume
If you're onboarding a handful of vendors a year, the free version of this control is checking the business yourself on your state's Secretary of State website before you cut the first check, slower and manual, but it's the same underlying data Middesk is querying by API. Revisit Middesk once that manual check becomes a bottleneck rather than an occasional five minutes. And remember Middesk only covers business-entity fraud, not individual identity, if your risk is a fake person rather than a fake company, that's Persona's job, and it has a free-to-start program a genuinely small team can actually use.
Bottom line
Worth it: businesses under 50 employees that regularly bring on new 1099 vendors or contractor entities and have engineering time to integrate an API. Not worth it yet: businesses that onboard a new vendor rarely, manually checking the registry costs nothing and takes minutes. See the full list of Middesk alternatives if your gap is individual identity or international coverage instead.