Not every contract has a single fixed price. This guide explains how to estimate variable consideration — discounts, bonuses, penalties, and rebates — and how the IFRS 15 constraint limits how much of it can be recognised as revenue before the uncertainty resolves.
- Two estimation methods: expected value and most likely amount
- The constraint: include only amounts highly probable not to reverse
- Five indicators that increase revenue-reversal risk
- Estimates must be reassessed every reporting period
- A full worked example of a construction performance bonus
Part 1: Fundamentals & the Five-Step Model · Part 2: Worked Examples · Part 3: Variable Consideration · Part 4: Contract Modifications · Part 5: Principal vs. Agent · Part 6: Licensing & Royalties
What Counts as Variable Consideration
Under IFRS 15, the transaction price is not always a fixed number stated in a contract. Whenever the amount an entity expects to receive can change because of discounts, rebates, refunds, credits, price concessions, incentives, performance bonuses, penalties, or other similar items, that portion of the price is variable consideration. It also arises when the entity’s entitlement to consideration depends on the occurrence or non-occurrence of a future event — for example, a bonus payable only if a construction project finishes ahead of schedule, or a penalty payable if a delivery is late.
Variable consideration is common in real contracts: sales-based rebates to distributors, volume discounts that apply retroactively once a customer crosses a purchase threshold, right-of-return provisions in retail, and service-level penalties in outsourcing agreements all fall into this category. The standard requires an entity to estimate the amount of variable consideration to include in the transaction price at contract inception, and to update that estimate at the end of each reporting period as circumstances change.
Two Estimation Methods: Expected Value vs. Most Likely Amount
IFRS 15 permits two estimation techniques, and the entity must use whichever method it expects to better predict the amount of consideration it will be entitled to. The choice is not a free election made once for the whole business — it should be applied consistently throughout the contract for a given type of variable consideration, based on which method the facts support.
- Expected value: the sum of probability-weighted amounts in a range of possible consideration outcomes. This approach tends to be more appropriate when a contract has a large number of possible outcomes with similar characteristics — for example, a portfolio of contracts with similar rebate terms across many customers.
- Most likely amount: the single most likely outcome in a range of possible outcomes. This approach tends to be more appropriate when a contract has only two possible outcomes — for example, an entity either achieves a performance bonus in full or does not achieve it at all.
The Constraint: Only Include Amounts Highly Probable Not to Reverse
Estimating variable consideration is only half of the requirement. IFRS 15 then applies a constraint: an entity includes some or all of an amount of variable consideration in the transaction price only to the extent that it is highly probable that a significant reversal in the amount of cumulative revenue recognised will not occur when the uncertainty is subsequently resolved.
This is a deliberately conservative test. It is not enough that the estimate is the entity’s best guess — management must also be confident that the number will not need to be walked back significantly once the uncertain event resolves. The constraint exists specifically to stop entities recognising revenue too early on highly uncertain variable amounts, a problem that was common in the pre-IFRS 15 environment for percentage-of-completion contracts with performance bonuses.
Indicators of a Significant Revenue Reversal Risk
IFRS 15 lists factors that increase the likelihood, or the magnitude, of a revenue reversal. The more of these factors that are present, the more of the variable consideration an entity should exclude from the transaction price until the uncertainty resolves.
| Factor Increasing Reversal Risk | Why It Matters |
|---|---|
| Consideration highly susceptible to factors outside the entity’s influence | Market volatility, judgment of third parties, weather, or actions of the customer make the outcome hard to predict reliably. |
| Long period before uncertainty resolves | More time means more opportunity for circumstances, and the estimate, to change materially. |
| Limited experience with similar contracts | Historical data is the main tool for a reliable estimate; new products or new customer types carry more risk. |
| Practice of offering broad price concessions | A pattern of changing prices after the fact undermines confidence in the stated transaction price. |
| Large number of possible outcomes with a wide range | A wide dispersion of possible amounts makes any single point estimate less reliable. |
Reassessing Estimates Each Reporting Period
The transaction price is not fixed once at contract inception and forgotten. IFRS 15 requires an entity to update its estimate of variable consideration, and to reassess the constraint, at the end of each reporting period, reflecting changes in circumstances since the previous reporting date. If a bonus that was previously excluded because it was not highly probable becomes highly probable, the cumulative catch-up is recognised as revenue in the period the assessment changes — not spread forward.
Worked Example: Applying the Constraint to a Performance Bonus
A contractor agrees to build a warehouse for a fixed fee of $2,000,000, plus a $150,000 bonus if the building is completed at least two weeks early. Based on the contractor’s experience with similar projects and current site conditions, management estimates an 80% probability of achieving the bonus.
Step 1 — Estimate: using the most likely amount method (only two outcomes: bonus achieved or not), the estimate is either $150,000 or $0.
Step 2 — Apply the constraint: at the start of the project, with significant weather and scheduling uncertainty remaining, management concludes it is not yet highly probable that including the bonus would avoid a significant revenue reversal. The transaction price is therefore set at $2,000,000 only.
Step 3 — Reassess: with four weeks remaining, the project is running two and a half weeks ahead of schedule and no material risks remain. Management now concludes it is highly probable the bonus will be achieved and that including it will not result in a significant reversal. The transaction price is updated to $2,150,000, with the cumulative catch-up recognised as revenue in the current period based on the project’s percentage of completion to date.
Common Mistakes
- Treating the “most likely amount” and “expected value” methods as interchangeable rather than choosing the one the facts actually support.
- Including variable consideration in the transaction price simply because it is probable, without separately applying the highly-probable-no-significant-reversal constraint.
- Failing to reassess the constraint every reporting period, and instead leaving an early estimate unchanged for the life of the contract.
- Ignoring the sales- and usage-based royalty exception (covered in Part 6 of this series) and applying the general constraint model to license royalties instead.
Not Sure If Your Estimates Meet the Constraint?
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