status: draft

Structural tests (OC/IC)

Structural tests measure whether the credit enhancement layers protecting noteholders remain intact. Unlike performance triggers that track collateral quality directly, structural tests measure the cushion between collateral value and debt obligations. When these tests fail, cash redirects to rebuild the cushion before flowing to originators.

Overcollateralization test mechanics

The OC test is the most important structural test in ABF. It compares the collateral principal balance to the outstanding note balance.

How the OC test works

OC Ratio = Collateral Principal Balance
           ────────────────────────────
           Outstanding Note Balance

Three key levels define OC test mechanics:

Level	Definition	Consequence of Breach
OC Target	Required ratio for full excess spread release	Below target: excess spread diverts to OC build
OC Floor	Minimum acceptable ratio	Below floor: sequential pay triggers; possible early amortization
OC Ratio	Current calculated ratio	Compared to target and floor each payment date

Reading OC test language in documents

Sample document language:

"OC Test" means, as of any Payment Date, the test that is satisfied when
the OC Ratio equals or exceeds the OC Target.

"OC Target" means 110.0%.

"OC Floor" means 105.0%.

"OC Ratio" means, as of any Determination Date, the ratio (expressed as
a percentage) of (a) the Aggregate Receivables Balance as of such date
to (b) the aggregate Outstanding Principal Amount of all Notes as of
such date.

Key parsing questions:

What’s in the numerator? Aggregate receivables balance, eligible receivables only, or mark-to-market value?
What’s in the denominator? All notes, or senior notes only (subordination-adjusted)?
What’s the measurement frequency? Daily, weekly, monthly, or each payment date?
What are the cure mechanics? Automatic cash diversion, or affirmative cure required?

The gap between target and floor

The operating range between OC Target and OC Floor is critical real estate:

Example:

OC Target: 110%
OC Floor: 105%
Current OC Ratio: 107%

The deal is below target but above floor. Consequences:

Excess spread diverts to build OC rather than releasing to originator
Deal continues operating normally in all other respects
If OC ratio recovers above 110%, excess spread release resumes

This is a soft failure. The originator receives $0 in residual until OC rebuilds, but the deal structure remains intact.

status: draft

Interest coverage test mechanics

The IC test measures whether available interest collections can service required interest payments on the notes.

How the IC test works

IC Ratio = Available Interest Collections
           ──────────────────────────────
           Required Interest Payments

IC test levels:

Level	Definition	Consequence
IC Target	Required ratio for normal waterfall priority	Below target: interest diverts from junior to senior
IC Floor	Minimum coverage (typically 1.0x)	Below floor: cannot fully pay senior interest from collections

IC test calculations

The numerator includes:

Interest collections from receivables
Fees collected
Investment income on reserve accounts
Recovery interest on charged-off loans

The denominator includes:

Senior note interest (required)
Mezzanine note interest (if applicable)
Servicing fees (if senior to note interest)
Trustee and administrative fees

When IC tests fail

An IC ratio below 1.0x means current period collections cannot fully pay required interest. This forces:

Interest shortfall allocation to junior notes
Reserve account draws to cover senior interest
Potential event of default if senior interest remains unpaid

status: draft

Debt service coverage ratio tests

DSCR tests appear primarily in commercial real estate and equipment transactions. They measure cash flow coverage of debt service.

How DSCR tests work

DSCR = Net Operating Income
       ────────────────────
       Debt Service (P&I)

DSCR test levels:

Asset Type	Typical DSCR Threshold	Consequence of Breach
CRE (stabilized)	1.20x - 1.40x	Cash trap or reserve replenishment
CRE (transitional)	1.10x - 1.25x	Loan maturity extension blocked
Equipment	1.15x - 1.30x	Sequential pay or reserve build

DSCR measurement variations

Debt yield: NOI divided by loan balance. Asset-focused alternative to DSCR.
Interest coverage only: NOI divided by interest payments (excluding principal). More lenient.
Amortizing vs. interest-only: DSCR during I/O period measures interest only; shifts to P&I at amortization start.

status: draft

Reading structural tests in documents

Waterfall conditional language

Structural tests typically appear as conditions within waterfall provisions:

(7) To the extent the OC Test is satisfied as of such Payment Date,
    to the Holder of the Residual Interest, any remaining amounts
    in the Collection Account.

(8) To the extent the OC Test is not satisfied as of such Payment
    Date, to the Principal Distribution Account for distribution
    as Principal Payments on the Notes in order of priority until
    the OC Test is satisfied.

This language means: if OC test passes, residual holder gets paid. If OC test fails, cash that would go to residual instead goes to pay down notes to rebuild OC.

Multiple structural tests

Deals often layer multiple tests. Each must pass for full excess spread release:

"Distribution Condition" means, as of any Payment Date, that each of
the following is satisfied: (i) the OC Test, (ii) the IC Test, and
(iii) no Early Amortization Event or Event of Default has occurred.

All three conditions must be met. Failure of any one causes cash diversion or worse consequences.

status: draft

OC/IC cushion management

Monitoring OC/IC cushion

Track your cushion monthly:

Metric	Calculation	Target
OC cushion	Current OC Ratio - OC Floor	>3% minimum
OC headroom	OC Target - Current OC Ratio	0% if you want distributions
IC cushion	Current IC Ratio - 1.0x	>0.25x minimum

What erodes OC/IC cushion

OC erosion sources:

Net losses reducing collateral balance faster than notes pay down
Prepayments (if collateral prepays faster than notes)
Mark-to-market declines (if fair value basis)
Ineligible collateral haircuts

IC erosion sources:

Rising delinquencies reducing interest collections
Interest rate increases on floating-rate notes (if assets are fixed)
Servicing cost increases
Reserve account depletion

Rebuilding OC/IC cushion

When tests fail, cash redirects to rebuild cushion:

Excess spread diversion: Residual cash that would flow to originator instead pays down notes or builds reserve
Pro rata to sequential conversion: Principal that would distribute pro rata now pays senior first, accelerating senior paydown
Turbo provisions: In stressed deals, 100% of collections may flow to senior paydown

The rebuild mechanics are automatic. The originator doesn’t choose to rebuild; the waterfall enforces it.

status: draft

Worked example: OC test cascade

Deal setup

Parameter	Value
Pool balance at close	$100M
Senior notes (Class A)	$80M
Mezzanine notes (Class B)	$10M
OC Ratio at closing	125% ($100M / $80M)
OC Target	120%
OC Floor	110%

Month 6: first stress

Pool balance declines to $92M due to losses and amortization. Class A balance: $78M (partial paydown)

OC Ratio = $92M / $78M = 118%

Status: Below OC Target (120%), above OC Floor (110%)

Consequence:

Excess spread diverts to Principal Distribution Account
Cash pays down Class A (sequential, not pro rata)
Originator distributions: $0

Month 12: deeper stress

Pool balance: $85M Class A balance: $72M

OC Ratio = $85M / $72M = 118%

Status: Still below target, still above floor

Consequence: Same as Month 6. Continuous OC build until ratio exceeds 120%.

Month 18: recovery

Pool balance: $78M Class A balance: $62M

OC Ratio = $78M / $62M = 126%

Status: Above OC Target (120%)

Consequence:

OC test passes
Excess spread releases to originator residual
Normal waterfall priority resumes

Month 24: floor breach

Pool balance: $65M (heavy losses) Class A balance: $60M

OC Ratio = $65M / $60M = 108%

Status: Below OC Floor (110%)

Consequence:

Sequential pay locks in permanently
Possible early amortization event
All collections flow to Class A until fully repaid
Originator distributions: $0 until full Class A/B repayment

status: draft

Common pitfalls with structural tests

Pitfall 1: confusing OC test failure with default

An OC test failure below target is not a default. It’s a cash management mechanism. The deal continues operating; cash just flows differently. Actual default requires a much more severe breach or extended non-compliance.

Pitfall 2: ignoring the numerator definition

The OC numerator might be:

Aggregate receivables balance (face value)
Eligible receivables only (excludes delinquent or ineligible assets)
Fair market value (mark-to-market)

These produce materially different ratios. An eligible-only numerator can drop sharply if delinquent assets are excluded from the calculation.

Pitfall 3: not modeling the rebuild timeline

When OC test fails, how long does it take to rebuild? This depends on:

Excess spread available for OC build
Remaining losses expected in the portfolio
Note amortization rate

Model the rebuild timeline. If it takes 18 months to rebuild OC at your expected loss rate, that’s 18 months of zero distributions.

Pitfall 4: IC test sensitivity to rate movements

Floating-rate notes with fixed-rate collateral create IC test risk when rates rise. Interest expense increases while interest income stays flat. Model IC ratio sensitivity to rate movements before closing.

status: draft

Cross-references

Triggers overview: severity spectrum and trigger categories
Performance triggers: delinquency, CNL, and charge-off triggers
The waterfall: how structural tests interact with payment priority
Advance rates: OC levels and borrowing base mechanics