IFRS 16 Discount Rate (IBR): How to Determine Your Incremental Borrowing Rate

Why the Discount Rate Matters

The discount rate is the single most judgment-intensive input in the IFRS 16 lease liability calculation — and the one with the greatest impact on the resulting balance sheet figures. A higher rate produces a lower liability; a lower rate produces a higher liability. The difference is not trivial.

Consider a straightforward commercial office lease: EUR 10,000 per month for 5 years. At a 4% discount rate, the initial lease liability is EUR 543,040. At 6%, it falls to EUR 517,256 — a difference of nearly EUR 26,000. For an entity with 50 leases across European offices, the aggregate impact of a 2% rate difference can reach millions of euros on the balance sheet.

This sensitivity creates two practical problems. First, the entity must construct a defensible rate for each lease (or group of leases). Second, auditors will challenge the methodology, inputs, and documentation. Getting the discount rate wrong — or failing to document how it was determined — is one of the most common audit findings in IFRS 16 compliance.

This guide covers the practical mechanics of constructing the incremental borrowing rate (IBR) for European businesses, with worked examples and sensitivity analysis. For the complete lease liability calculation, see our step-by-step liability guide or use the IFRS 16 calculator.

Rate Implicit in the Lease vs IBR

IFRS 16 establishes a hierarchy for the discount rate:

1. Rate implicit in the lease — the rate that causes the present value of lease payments plus the unguaranteed residual value to equal the fair value of the underlying asset plus the lessor's initial direct costs
2. Incremental borrowing rate (IBR) — the rate the lessee would have to pay to borrow over a similar term, with similar security, the funds necessary to obtain an asset of a similar value in a similar economic environment

Why the Implicit Rate Is Rarely Available

The rate implicit in the lease requires knowledge of the lessor's expected residual value and the fair value of the underlying asset. For property leases, the lessee almost never has access to this information. The lessor may not disclose it, and the calculation involves assumptions about the property's value at lease end that are specific to the lessor's position.

In practice, the implicit rate is available primarily for equipment leases where the lessor is also the manufacturer or dealer (e.g., vehicle leases from captive finance companies that disclose the rate). For the vast majority of commercial property leases — which make up the bulk of European lease portfolios — the IBR is the operative rate.

The IBR Definition Unpacked

The IFRS 16 definition of the IBR contains four specific requirements that constrain how the rate is constructed:

Each of these requirements has practical implications for rate construction.

IBR Construction Methodology

The IBR is typically built up from three (sometimes four) components:

IBR = Risk-Free Rate + Credit Spread − Collateral Adjustment (± Currency Adjustment)

Component 1: Risk-Free Rate

The risk-free rate is the foundation. It should match the lease term and the currency of the lease payments.

For EUR-denominated leases:

The most common reference rates are:

• Euro area government bond yields — German Bunds are the standard proxy for the EUR risk-free rate. Use the yield-to-maturity on bonds with a remaining term matching the lease term.
• ECB deposit facility rate — useful as a short-term reference, but less appropriate for leases longer than 1–2 years because it does not reflect the term structure.
• Euro swap rates (IRS) — the mid-market EUR interest rate swap curve provides clean, liquid term-matched rates and is widely used by banks and auditors.

Example (March 2026):

Either reference is acceptable, provided the entity applies it consistently and documents the choice. The swap rate is marginally higher because it includes a small interbank credit component, but both are defensible.

For other European currencies:

For multi-currency lease portfolios, the risk-free rate must be matched to each lease's payment currency. A EUR-denominated lease in Paris and a GBP-denominated lease in London require different risk-free rates.

Component 2: Credit Spread

The credit spread reflects the entity's creditworthiness — the premium over the risk-free rate that a lender would charge to compensate for the entity's default risk.

If the entity has a credit rating:

Use the corporate bond spread for the entity's rating and the relevant term. Rating agencies (Moody's, S&P, Fitch) publish these, and market data providers (Bloomberg, Refinitiv) offer credit spread curves.

If the entity does not have a credit rating:

Most mid-market European companies do not carry a public credit rating. In this case, estimate a "shadow" credit rating using:

• Bank lending rates — the entity's actual borrowing rate on existing facilities provides a market-validated data point. Adjust for any collateral differences between the bank loan and the lease.
• Financial ratios — map the entity's leverage, interest coverage, and profitability metrics to the credit rating scales published by rating agencies.
• Industry benchmarks — use sector-specific credit spread data from industry associations or audit firm publications (Deloitte, PwC, EY, and KPMG all publish IFRS 16 IBR guidance).

A mid-market European company with moderate leverage, stable cash flows, and no public rating typically falls in the BBB/BB range (1.5%–3.0% spread).

Component 3: Collateral Adjustment

The IBR must reflect a secured borrowing — specifically, borrowing secured by an asset similar to the right-of-use asset. Since secured borrowing rates are lower than unsecured rates, a collateral adjustment reduces the IBR.

The size of the adjustment depends on the nature of the underlying asset:

Real estate leases receive the largest collateral adjustment because the underlying property provides strong security. Equipment with low resale value or rapid depreciation provides less security and warrants a smaller adjustment.

Component 4: Currency Adjustment (Cross-Border Leases Only)

If an entity borrows in one currency but makes lease payments in another, a currency adjustment may be necessary. For most European entities, this arises with:

• A German parent company (EUR borrower) with a UK subsidiary lease (GBP payments)
• A Dutch entity with a Swiss lease (CHF payments)

The adjustment reflects the interest rate differential between the two currencies. In practice, it is simpler to construct the IBR entirely in the lease payment currency using that currency's risk-free rate and credit spread data.

Worked Example: Constructing the IBR

Entity: Mid-market German logistics company, no public credit rating Lease: 5-year office lease in Frankfurt, EUR 10,000/month Date: 1 January 2026

The resulting 4.0% IBR produces an initial lease liability of EUR 543,040 for this 5-year, EUR 10,000/month lease.

Sensitivity Analysis

The discount rate has a material impact on the lease liability. Before finalising the IBR, it is good practice to run a sensitivity analysis to quantify the effect of alternative rates.

Sensitivity Table: EUR 10,000/Month, 5-Year Lease

Key observations:

• Each percentage point change in the IBR shifts the lease liability by approximately EUR 12,000–EUR 13,000 for this lease size and term
• The relationship is approximately linear for rates in the 2%–7% range but becomes non-linear at extreme rates
• A 2% difference (e.g., 3% vs 5%) produces a swing of EUR 26,470 — nearly 5% of the total liability

Sensitivity for Different Lease Terms

The discount rate impact increases with the lease term. Longer leases have more payments to discount, so each basis point has a compounding effect:

For a 10-year property lease at EUR 10,000/month, a 2% IBR difference produces a liability swing of nearly EUR 90,000. For entities with large property portfolios, the aggregate sensitivity can be substantial.

European-Specific Considerations

ECB Monetary Policy and IBR

The European Central Bank's monetary policy directly affects the risk-free component of the IBR. The ECB's deposit facility rate and its impact on government bond yields create a common baseline for all EUR-denominated leases. When the ECB raises rates, new lease IBRs increase; when rates fall, new lease IBRs decrease.

Importantly, existing lease IBRs are generally not updated for changes in market interest rates. The IBR is locked in at commencement. Only specific remeasurement events (lease modifications, option reassessments) trigger a rate update — and when they do, the new rate applies prospectively.

Eurozone vs Non-Eurozone EU Countries

European entities operating across EU member states face currency-related IBR complexity:

• Eurozone leases (EUR): A single risk-free curve applies. The credit spread and collateral adjustment may vary by jurisdiction (e.g., commercial property values differ between Germany and Portugal), but the base rate is common.
• Non-Eurozone EU leases (PLN, CZK, HUF, SEK, DKK, RON, BGN): Each currency has its own yield curve and risk-free rate. A Polish subsidiary's PLN-denominated lease requires a PLN-based IBR, even if the parent reports in EUR.

Country-Specific Yield Curve Sources

Portfolio Approach vs Lease-by-Lease

IFRS 16 permits a portfolio approach to discount rates. Instead of determining a unique IBR for each individual lease, entities can group leases with similar characteristics and apply a single rate to the portfolio.

When the Portfolio Approach Works

The portfolio approach is acceptable when the leases in the group share:

• Similar remaining lease terms — within a band (e.g., 4–6 years)
• Same currency — all EUR, or all GBP
• Similar economic environment — same jurisdiction or comparable markets
• Consistent entity credit profile — determined at the same date or during a period when the entity's credit risk was stable

Practical Implementation

Most entities define IBR "buckets" by lease term and currency:

New leases are assigned to the appropriate bucket based on their characteristics. The IBR for each bucket is updated periodically (typically quarterly) to reflect current market conditions.

When Lease-by-Lease Is Necessary

A lease-by-lease approach is required when:

• The entity has a small number of individually material leases
• Lease terms, currencies, or jurisdictions vary significantly
• The entity's credit profile has changed materially during the period
• Auditors require granular documentation for specific high-value leases

In practice, many entities use a hybrid approach: a portfolio methodology for the bulk of their leases (vehicles, office equipment, standard offices) and individual IBR determinations for large or unusual leases (headquarters, distribution centres, cross-border arrangements).

Common Mistakes

1. Using a Single Rate for All Leases

Applying one IBR across all leases regardless of term, currency, and asset type is the most frequently challenged approach in audit. A 2-year vehicle lease and a 12-year headquarters lease in different currencies should not share a discount rate. The portfolio approach requires grouping by similar characteristics — not dumping all leases into one bucket.

2. Ignoring the Term Structure

Using the entity's existing bank borrowing rate (e.g., a 3-year revolving credit facility rate) as the IBR for a 10-year property lease ignores the term premium. Longer-term borrowing rates are almost always higher than shorter-term rates. The IBR must reflect the lease term, not the term of the entity's existing debt.

3. Using Stale Rates

The IBR should be determined at or near the commencement date. Using a rate determined 6 months earlier, when market conditions were different, undermines the measurement. Many entities solve this by determining the IBR quarterly and applying the most recent rate to leases commencing in that quarter.

4. Forgetting the Collateral Adjustment

The IBR is a secured borrowing rate. If the entity starts with its unsecured bank borrowing rate, it must subtract a collateral adjustment to reflect the security provided by the underlying asset. Omitting this adjustment overstates the IBR and understates the lease liability.

5. Not Documenting the Methodology

Auditors expect to see a documented IBR policy that describes:

• The risk-free rate source and selection methodology
• How the credit spread is determined (credit rating, bank facility rate, financial ratio mapping)
• The collateral adjustment approach and amount
• Whether a portfolio or lease-by-lease approach is used
• How frequently the IBR is updated
• Data sources and dates of determination

Without documentation, even a correctly constructed IBR is vulnerable to audit challenge.

6. Updating the IBR for Market Rate Changes

The IBR is set at lease commencement and is not updated merely because market interest rates have changed. It is only revised when:

• The lease term is reassessed (e.g., an extension option becomes reasonably certain)
• The lease is modified
• Certain other remeasurement events occur under IFRS 16.42

CPI-linked rent escalation, the most common remeasurement event for European property leases, uses the original IBR — not an updated rate.

Documentation Requirements for Auditors

A defensible IBR determination requires clear documentation. Auditors typically request the following:

IBR Policy Document

A standing policy document (updated annually) that describes:

1. Risk-free rate selection: Which benchmark (government bond yields, swap rates), which maturity matching approach, which data provider
2. Credit spread methodology: How the entity determines its credit spread — rating-based, bank facility–based, or financial ratio–based
3. Collateral adjustment: How the adjustment is calculated, evidence for the quantum
4. Portfolio grouping criteria: How leases are grouped (if applicable), term bands, currency bands
5. Update frequency: How often the IBR is refreshed (quarterly is standard practice)
6. Governance: Who approves the IBR, what review process exists

Per-Lease (or Per-Portfolio) Documentation

For each IBR determination, document:

Supporting Evidence

• Screenshot or printout of the risk-free rate from the data provider at the relevant date
• Entity's bank facility agreement showing the borrowing margin
• Credit rating letter (if available) or internal credit assessment workpaper
• Market data supporting the collateral adjustment (e.g., secured vs unsecured lending rates)

Summary

The incremental borrowing rate is not a number you can look up in a table. It is a constructed rate that reflects the entity's specific circumstances — its creditworthiness, the lease term, the currency, and the nature of the underlying asset. Getting it right requires a systematic methodology, appropriate market data, and clear documentation.

For European businesses, the IBR construction is anchored by ECB monetary policy and Euro area yield curves, with adjustments for entity-specific credit risk and the security value of the leased asset. The portfolio approach offers practical relief for entities with many similar leases, but high-value or unusual leases warrant individual determination.

To calculate the lease liability using your determined IBR, use our IFRS 16 calculator or follow the step-by-step liability calculation guide. For guidance on the ROU asset that sits on the other side of the balance sheet, see our IFRS 16 ROU asset guide.