What is Day 1 Certainty?
Day 1 Certainty (D1C) is a Fannie Mae program that allows lenders to use automated verification sources for income, assets, and employment. When using D1C-approved sources, lenders can:- Accept verified data without requiring additional documentation
- Reduce conditions and tasks
- Accelerate the loan process
- Improve borrower experience
What is AIM?
Asset and Income Modeler (AIM) is Freddie Mac’s equivalent program that provides automated verification of income and assets. AIM offers similar benefits to D1C:- Automated income and asset verification
- Reduced documentation requirements
- Faster loan processing
- Fewer conditions
Why D1C and AIM matter
No manual entry
Borrowers don’t need to manually enter income, assets, or employment
information
Fewer tasks
No need to task out for documentation because data is approved via Fannie
and Freddie approved sources
Path of least resistance
Generates the path of least resistance with the least amount of conditions
Programmatic
Essential for programmatic loan origination where manual intervention should
be minimized
How it works
When you use D1C and AIM-approved verification sources:1
Borrower provides minimal info
Borrower provides basic information (e.g., SSN for income verification,
connects bank account for assets).
2
Automated verification
Pylon pulls verified data from approved sources (e.g., The Work Number for
income, Plaid for assets).
3
Fannie/Freddie approval
Data is verified through Fannie Mae and Freddie Mac approved sources,
meeting D1C and AIM requirements.
4
Reduced conditions
Since data is pre-verified, underwriting requires fewer conditions and
tasks, accelerating the loan process.
Coverage and maturity
High coverage: Both D1C and AIM ecosystems are quite mature with >90%
coverage of banks, payroll providers, and other data sources. This means most
borrowers can benefit from automated verification.
- Payroll providers: Most major HRIS systems and payroll processors
- Banks and financial institutions: Coverage of major banks and credit unions
- Employment verification: Automated employment and income verification
- Asset verification: Bank account and asset verification
Best practices
- Use approved sources: For generating the path of least resistance with the least amount of conditions, use D1C and AIM approved sources whenever possible.
- Prioritize automated verification: When borrowers have access to approved sources, use them instead of manual entry and documentation.
- Explain the benefits: Help borrowers understand that using automated verification speeds up their loan and reduces paperwork.
- Fallback gracefully: If automated verification isn’t available for a borrower, fall back to traditional documentation methods.
Available integrations
Pylon currently supports the following D1C and AIM approved sources:- The Work Number - Income and employment verification (D1C and AIM approved)
- Plaid - Asset verification (D1C and AIM approved for assets)
Pylon continues to evaluate additional D1C and AIM approved sources. Check
with your Pylon representative for the latest available integrations.
When to use D1C and AIM
Use D1C and AIM approved sources when:- Borrower’s employer uses supported payroll provider: If the borrower’s employer uses The Work Number or another supported system, use automated income verification.
- Borrower’s bank is supported: If the borrower’s bank is supported by Plaid or other asset verification providers, use automated asset verification.
- Programmatic origination: For programmatic loan origination, automated verification is essential to minimize manual intervention.
- Speed is critical: When you need to close loans quickly, automated verification reduces processing time.
Related resources
- Income Verification - Learn about The Work Number integration
- Asset Verification - Learn about Plaid integration
- Order-Outs Overview - Understand when automated verifications are triggered