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Definition

Sustainability-linked bond Definition

A sustainability-linked bond is debt whose financial or structural terms change according to whether the issuer meets predefined sustainability performance targets by specified dates.

What is a sustainability-linked bond?

A sustainability-linked bond (SLB) ties a bond term to the issuer's performance against predefined sustainability performance targets (SPTs). A key performance indicator (KPI) measures the result. The SPT sets the result and observation date that determine whether a trigger event occurs.

The proceeds can fund general corporate purposes because performance, not allocation, defines the instrument. This is the performance-linked structure described in Keslio's sustainable financing guide. The voluntary 2024 Sustainability-Linked Bond Principles (SLBP) cover five components: KPI selection, SPT calibration, bond characteristics, reporting, and verification.

Why does a sustainability-linked bond matter to you?

Treasury may lead the bond issuance, but finance, operations, facilities and sustainability teams usually own the KPI records. Before issuance, investors and any external reviewer will examine whether the KPI is material to the business, its scope and method are clear, the baseline can be checked, and the SPT goes beyond business as usual.

After issuance, a missed SPT can change the issuer's financing cost. A coupon step-up increases the interest rate from the date written into the bond documents. The documents can also specify consequences for a missed reporting or verification condition. If the business boundary, baseline, observation date or trigger wording differs across the framework, bond documents and data workbook, the issuer may be unable to prove which result applies.

How does a sustainability-linked bond work?

First, select a KPI that is material, measurable, consistently calculated, externally verifiable and capable of comparison. Second, set an ambitious SPT with a stated baseline, benchmark, calculation method, observation date and trigger event. Third, write the financial or structural change into the bond documents. For a coupon step-up, specify the adjustment, accrual date, payment frequency, treatment of multiple KPIs and any fallback if a KPI cannot be calculated.

Fourth, publish current KPI performance and the related effect on the bond at least annually and for each relevant assessment date. Fifth, obtain independent external verification of performance against each SPT once a year and at every assessment date that can change the bond, through the last trigger event. A pre-issuance second-party opinion is recommended under the SLBP; post-issuance verification is a necessary component of SLBP alignment.

What mistakes should you avoid?

  • Treating an SLB like a green bond and trying to prove that every dirham financed an eligible project.
  • Selecting a KPI that covers a small or convenient part of the business while excluding material operations.
  • Stating a coupon step-up without its trigger, accrual date, payment frequency, maximum cumulative change or fallback.
  • Changing the KPI method, baseline or perimeter after issuance without applying the documented adjustment rules and review process.

How is a sustainability-linked bond different from a green bond?

An SLB tests company performance against KPIs and SPTs, while its proceeds can normally support general corporate purposes. A green bond reserves its proceeds, or an equivalent amount, for eligible green projects. A green project does not make a weak SLB target credible, and a strong SPT does not turn general proceeds into green-bond proceeds.

What should you give investors and reviewers?

Provide the bond framework and documents, the KPI definition and business boundary, the calculation method, baseline, historical values, SPT, benchmark, observation and notification dates, trigger mechanics, fallback and recalculation rules, and reporting timetable. Include the pre-issuance review, annual performance reports and public verification reports.

Are the Sustainability-Linked Bond Principles mandatory?

No. The SLBP are voluntary market guidance. The issuer's bond documents, securities rules and applicable law can create binding duties, and applicable law prevails if it conflicts with the principles. State exactly which SLBP version the issuer claims to follow.

Example

Suppose a hypothetical facilities-services company in the UAE issues an AED 100,000,000 five-year SLB in 2026. Its KPI is absolute Scope 1 and Scope 2 emissions from its owned fleet and offices. The verified 2025 baseline is 4,000 tCO2e, and the SPT is 3,000 tCO2e at the 31 December 2028 observation date, a 25% reduction.

The bond pays a 5.00% annual coupon. Its documents state that a verified result above 3,000 tCO2e triggers a 25-basis-point coupon step-up from 1 January 2029 for the final two years. The verified result is 3,200 tCO2e. That is 200 tCO2e above the target and a 20% reduction from the baseline, so the SPT is missed.

Before the step-up, annual interest is AED 100,000,000 x 5.00% = AED 5,000,000. After the step-up, it is AED 100,000,000 x 5.25% = AED 5,250,000. The extra cost is AED 250,000 a year, or AED 500,000 across two full years if the principal remains outstanding. The scenario is hypothetical; the target's materiality, ambition and benchmark would still need review.

Where it comes up

ICMA SLBP selection of KPIs and calibration of SPTsSustainability-Linked Bond Principles 2024, Core Components 1 and 2, pages 3-4Official sourceICMA SLBP bond characteristics and coupon variationSustainability-Linked Bond Principles 2024, Core Component 3, page 5; Appendix II, page 8Official sourceICMA SLBP reporting and post-issuance verificationSustainability-Linked Bond Principles 2024, Core Components 4 and 5, page 5Official source

Related terms

Green Bonds

A green bond is a bond whose proceeds are reserved for eligible projects with environmental benefits; the label applies to the financing, not automatically to the issuer's whole business.

Materiality

Materiality is the test a company uses to decide which sustainability topics matter enough to manage or report because they could affect its finances, reflect significant impacts on people or the environment, or both.

Responsible Investing

Responsible investing considers environmental, social and governance information when investors allocate capital, manage holdings and use their influence to pursue stated financial objectives and, where applicable, sustainability objectives.

Sustainability Reporting

Sustainability reporting is the process of publishing evidence-backed information about a company's environmental, social, and governance impacts, risks, opportunities, policies, targets, and performance for a defined period and business boundary.

Sustainability performance target (SPT)

A sustainability performance target (SPT) is a measurable result set for a key performance indicator by a fixed observation date, with financing terms changing according to whether the result is achieved.

Sources

Last verified 2026-08-19

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Sustainability-linked bond Definition | Keslio