Proofstackby Classifi

Hire contractors who are
already verified.

The Proofstack verified contractor network gives Classifi employers access to independent contractors with documented compliance — W-9 on file, independence verified, audit risk reduced before day one.

Built on Classifi's compliance infrastructure — developed by a former Indiana DWD state auditor who conducted employer misclassification audits.

10+

Verified contractors and growing

Growing

Expanding nationwide

Building

Confirmed engagements

Multiple

Industries represented

The risk

Every unverified contractor relationship is an assumption.

Unemployment insurance audit exposure

If a state auditor determines your contractor should have been classified as an employee, you owe back UI taxes, penalties, and interest. The burden of proof is on you.

📄

Documentation scramble

When an audit notice arrives, employers scramble to reconstruct independence documentation that should have been collected at the start of every engagement. Most can’t.

Onboarding friction at scale

Collecting W-9s, verifying insurance, documenting independence signals — manually, for every contractor, at the start of every engagement — is expensive, inconsistent, and error-prone.

The solution

Proofstack Verified contractors arrive audit-ready.

What the contractor brings

  • W-9 on file and verified
  • Independence signals documented (ABC test mapped)
  • Liability insurance certificate on file
  • Business entity confirmed
  • Engagement history with concurrent client proof
  • Proofstack Verified badge

What this means for the employer

  • No W-9 collection — it’s already there
  • No independence documentation scramble
  • Audit defense foundation built before day one
  • Onboarding time: minutes, not days
  • Compliance confidence from first payment

How it works

Three steps to compliant contractor relationships.

1

Search the verified network

Filter by industry, location, skills, and verification level. Every result is a contractor who has documented their independence through Proofstack.

2

Start the engagement

Click ‘Start engagement’ on any profile. Their W-9 pulls automatically into your Classifi workspace. Their independence signals are available as your audit documentation basis.

3

Stay compliant automatically

Classifi tracks payments, monitors 1099 thresholds, alerts you to compliance events, and keeps the engagement record clean. If an audit ever comes, your packet is already built.

Two levels of verified.

Self-documented independence signals reviewed against the ABC test. W-9 on file. Searchable in the employer network. The standard for compliant contractor relationships.

From $12/month (contractor pays — not employer)

Human review by the Classifi compliance team — former DWD state auditors. Independence assessment memo issued. The highest trust level for enterprise contractor relationships.

From $29/month (contractor pays — not employer)

Verification is paid by the contractor, not the employer. Employers access the verified network through their Classifi subscription.

The verified contractor network is growing.
Be among the first employers to access it.

Classifi employers who join early shape the network — inviting their contractors to Proofstack and building the verified supply their industry needs.