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IFRS 9 Expected Credit Loss (ECL) Model: Three-Stage Impairment with Worked Examples

By Usman Qureshi (ACCA, ACA) · Published July 2026 · Last reviewed July 2026 · 14 min read

The Expected Credit Loss (ECL) model is the heart of IFRS 9. It requires you to recognize losses before a borrower defaults — not after. This guide walks through the three-stage model, SICR identification, ECL calculation (PD × LGD × EAD), and real-world audit challenges including post-model adjustments, forward-looking info, and the common mistakes that cost auditors hundreds of hours.

In this guide

What is ECL and Why It Matters

Under IAS 39 (the old standard), you recognized losses only when evidence of impairment existed — typically when a payment was late or default occurred. This is the "incurred loss" model.

IFRS 9 flipped the model to forward-looking: you estimate the probability of default and recognize an allowance even for performing assets. This reflects economic reality: a loan made today has some probability of defaulting in the future, so that risk should be recognized now.

The Three-Stage ECL Model

IFRS 9 uses three stages to determine how much ECL to recognize:

Stage Asset Status ECL Type Trigger
Stage 1 Performing (Low credit risk) 12-month ECL No SICR since recognition
Stage 2 Underperforming (Increased risk) Lifetime ECL SICR occurred, but not in default
Stage 3 Credit-impaired (In default) Lifetime ECL Default criteria met (>90 days arrears, bankruptcy, etc.)

Stage 1: Performing Assets (12-Month ECL)

Most financial assets start in Stage 1 when initially recognized. The ECL allowance covers only the probability of default within the next 12 months.

ECL Calculation for Stage 1

ECL = PD (12-month) × LGD × EAD

Example: Bank mortgage, Stage 1

ECL = 0.15% × 25% × £300,000 = £1,125

The bank records a loss allowance of £1,125 against this mortgage, even though the borrower is current and paying on time.

Stage 2: Underperforming Assets (Lifetime ECL at SICR)

When credit risk increases significantly, the asset moves to Stage 2. Now you recognize the full lifetime ECL — the probability of default any time in the remaining life of the asset.

ECL Calculation for Stage 2

ECL = PD (lifetime) × LGD × EAD

Same mortgage, now in Stage 2 (SICR triggered)

ECL = 2.5% × 30% × £290,000 = £21,750

The loss allowance jumped from £1,125 to £21,750. The increase (£20,625) is recognized as an impairment loss in P&L.

SICR Indicator: What Triggered the Move?

Possible triggers for this mortgage:

Stage 3: Credit-Impaired Assets (Default & Lifetime ECL)

When an asset meets the default criteria (typically >90 days past due, bankruptcy filing, or unlikely to pay), it moves to Stage 3. The ECL remains lifetime, but recovery expectations are more pessimistic.

ECL Calculation for Stage 3

ECL = PD (100%, assumed default) × LGD × EAD

Same mortgage, now in Stage 3 (Default)

ECL = 100% × 45% × £280,000 = £126,000

The full loss allowance is £126,000. Interest income on this mortgage is now calculated on the net amount (£280,000 −’ £126,000 = £154,000), not the gross balance.

SICR Triggers and Thresholds

SICR is the judgment call that determines when to move assets from Stage 1 to Stage 2. It's also where auditors spend the most time.

Quantitative SICR Triggers

Portfolio Type SICR Threshold Example
Retail mortgages 30 days arrears OR PD →‘ 200 bps Payment 30+ days late; or PD from 0.5% to 2.5%
Credit cards 60 days arrears OR PD →‘ 150 bps Account delinquent; or risk premium increased
Corporate loans Covenant breach OR credit rating downgrade ≥2 notches OR PD →‘ 300 bps Debt/EBITDA covenant breached; or S&P downgraded to speculative

Qualitative SICR Triggers

Audit Challenge: Many banks set SICR thresholds too conservatively (e.g., 500 bps PD increase). Auditors push back: "Market guidance is 300 bps. Your higher threshold delays Stage 2 movement and understates ECL." Result: ECL increases by 5— 10%+ in final audit adjustments.

PD, LGD, EAD: The Three Components

PD (Probability of Default)

Definition: The % probability that a borrower will default within a specified time frame (12 months for Stage 1, lifetime for Stage 2/3).

Estimation methods:

LGD (Loss Given Default)

Definition: The % of exposure that is lost if the borrower defaults.

Components: LGD = (EAD −’ Recovery) / EAD

Estimation methods:

EAD (Exposure at Default)

Definition: The total amount outstanding at the time of default.

For a term loan: Simply the principal outstanding

For a credit facility: Drawn amount + estimated future drawings

Worked Example: Mortgage Portfolio ECL

Bank's Retail Mortgage Portfolio (31 Dec 2025)

Stage 1 Calculation

Parameters: PD 12m = 0.18%, LGD = 25%, EAD = £1.8bn

ECL = 0.18% × 25% × £1.8bn = £810,000

Stage 2 Calculation

Parameters: PD lifetime = 2.2%, LGD = 28%, EAD = £160m

ECL = 2.2% × 28% × £160m = £9,856,000

Stage 3 Calculation

Parameters: PD = 100%, LGD = 42%, EAD = £40m

ECL = 100% × 42% × £40m = £16,800,000

Total ECL Allowance

£810k + £9,856k + £16,800k = £27,466,000

Journal Entry (31 December 2025):

Dr Impairment Loss on Financial Assets                                                                                                         27,466,000
    Cr Loss Allowance on Mortgages                                                                                                                                                       27,466,000

Worked Example: Corporate Loan Portfolio Movement

Scenario: Technology Company Loan (1-Year Period)

1 January 2025: Initial recognition (Stage 1)

30 June 2025: SICR occurs (moves to Stage 2)

Journal Entry (30 June 2025):

Dr Impairment Loss (SICR adjustment)                                                                                                                                                                         1,592,750
    Cr Loss Allowance on Loan                                                                                                                                                                                                                      1,592,750

(The increase from £28k to £1,620,750 is £1,592,750 of incremental impairment loss.)

Post-Model Adjustments (PMAs)

Many banks don't rely solely on the mechanical ECL formula. They apply "post-model adjustments" for factors the model doesn't capture:

Audit Challenge: PMAs are subjective. Auditors scrutinize: "How did you justify a £5m PMA? Is it documented? Is it reversible or permanent? How does it correlate to your forward-looking info?"

Audit Red Flags in ECL

Red Flag 1: Stage 2 Thresholds Too High

Finding: Bank's SICR threshold is 500 bps PD increase; market standard is 300 bps.

Auditor action: Recalculate ECL using 300 bps threshold; estimate the impact (+£8m); propose adjustment.

Red Flag 2: Lack of Documentation

Finding: No written policy on how SICR is identified; asset reclassifications appear arbitrary.

Auditor action: Require documented SICR policy, then retroactively reclassify assets under that policy.

Red Flag 3: PMAs Unexplained

Finding: Management applied a £10m PMA for "general economic uncertainty" but provided no detailed justification.

Auditor action: Challenge the PMA; often it's reduced or eliminated.

Red Flag 4: Interest Income Misstatement in Stage 3

Finding: Bank continues to recognize interest on Stage 3 loans using the gross carrying amount, not the net amount (gross −’ allowance).

Auditor action: Correct interest income; likely a £2— 5m adjustment for large Stage 3 portfolios.

UQ

Usman Qureshi (ACCA, ACA)

ECL is where Big 4 auditors spend the most time on financial instruments. I've audited bank portfolios with £500m+ in ECL allowances. The three-stage model is elegant in theory but brutal in judgment-call battles during audit execution.

Real-Life Case Study: Staging a Loan Under the ECL Model

Scenario. A lender advances £1m to a corporate borrower. Over 18 months the borrower's credit deteriorates.

  • Origination (Stage 1): 12-month ECL, say £5k provision.
  • Significant increase in credit risk (Stage 2): after two covenant breaches, lifetime ECL, provision jumps to £60k, even though no payment is missed.
  • Credit-impaired (Stage 3): borrower misses payments, interest now recognised on the net (post-provision) carrying amount.

Takeaway. The big P&L hit comes at the Stage 1→2 move, driven by change in risk since origination, not by an actual default. Auditors focus hard on the SICR triggers because that is where judgement, and provision size, is greatest.

Illustrative composite scenario for educational purposes. Figures are indicative and do not represent any specific company.

Related Articles in This Cluster

→ IFRS 9 Financial Instruments Hub

• IFRS 9 Classification & Measurement: Business Model Test & SPPI Explained

• IFRS 9 Hedge Accounting: Cash Flow & Fair Value Hedges with Effectiveness Testing

• IFRS 9 Impairment Accounting: Lifetime ECL vs 12-Month ECL & Stage Movements

• IFRS 9 Modification & Derecognition: Loan Changes, Forgiveness & Exit Accounting

Disclaimer: This is educational content. IFRS 9 ECL application is highly fact-specific and requires professional judgment. Consult a qualified accountant or auditor for your specific circumstances.