ASC 842 Common Mistakes: 2026 Practitioner Walkthrough

ASC 842 has been fully effective for public companies since fiscal year 2019 and for private companies since fiscal year 2022. Yet audit findings, restatements, and SEC comment letters on lease accounting keep surfacing. The errors are not a transition-year hangover. They reflect an ongoing operational failure: lease portfolios change constantly, and most companies built a project to adopt ASC 842 rather than a process to maintain it.

This walkthrough covers the eight most consequential error patterns, grounded in FASB codification, Big-4 technical guidance, SEC comment letter trends, and PCAOB inspection findings. It also covers ASU 2023-01 (Common Control Arrangements), effective for fiscal years beginning after December 15, 2023, which the vendor-blog articles ranking on this topic have entirely missed.

Key takeaway: The audit backstop is not catching all ASC 842 errors. PCAOB 2023 inspection reports flagged that auditors themselves are making mistakes in testing IBR assumptions and lease population completeness. Your internal controls are the real line of defense.

What Are the Most Common ASC 842 Mistakes?

The five error clusters that generate the most audit adjustments and restatements are: incomplete lease population identification, incorrect lease term determination, discount rate errors, modification and remeasurement failures, and inadequate disclosures. Three additional areas, ASU 2023-01 leasehold improvements, ROU asset impairment, and sale-leaseback classification, round out the risk picture. Each is covered below with the mechanism that causes it and the fix.

Mistake 1: Incomplete Lease Population (Including Embedded Leases)

The most common ASC 842 error is not knowing what you have. Under ASC 842-10-15-3, a contract contains a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. That definition sweeps in arrangements that are labeled as service contracts, outsourcing agreements, or supply contracts.

As FASB ASC 842-10-15-9 states: "Identifying whether a contract contains a lease requires significant judgment. The key question is whether the customer has the right to obtain substantially all of the economic benefits from use of an identified asset and the right to direct the use of that asset throughout the period of use."

Common embedded lease scenarios that get missed:

• Dedicated server capacity in IT outsourcing contracts
• Dedicated manufacturing lines in contract manufacturing agreements
• Dedicated transportation assets in logistics contracts
• Warehouse space allocated exclusively to one customer

Why it happens: Procurement and IT sign these contracts without looping in accounting. The word "lease" never appears in the document. PwC's lease accounting guide identifies embedded lease identification as one of the most judgment-intensive and error-prone areas of ASC 842, specifically because many companies failed to involve procurement and IT in the initial scoping exercise.

The fix:

1. Build a contract review workflow that routes new service, outsourcing, and supply agreements through accounting before execution.
2. Re-run a population completeness check annually, not just at adoption. Focus on IT, logistics, and manufacturing contracts above a defined dollar threshold.
3. Document the analysis for contracts where you conclude no lease exists. The absence of a lease needs to be supportable, not just assumed.

Mistake 2: Incorrect Lease Term Determination

Lease term errors are a top source of misstated lease liabilities, and they run in both directions: companies over-include optional periods they will never exercise, and under-include periods they almost certainly will.

Under ASC 842-10-25-2, the lease term includes the non-cancellable period plus optional renewal periods that are "reasonably certain" to be exercised. "Reasonably certain" is a high bar, equivalent to "reasonably assured" under legacy ASC 840. It is not "more likely than not."

The short-term lease exemption under ASC 842-10-55-28 adds another trap: a lease qualifies for the 12-month exemption only if the total reasonably certain term, including renewal options, is 12 months or less at commencement. A lease with a stated initial term of 11 months and a renewal option the company is reasonably certain to exercise does not qualify.

Why it happens: Renewal option probability assessments are subjective and poorly documented. Deloitte's ASC 842 roadmap flags this as a significant error source, noting that companies frequently either over-include or under-include optional periods.

The fix:

• Document the specific economic factors supporting each renewal probability conclusion at commencement (e.g., significant leasehold improvements, location criticality, relocation costs).
• Build a calendar to reassess renewal options when significant events occur, such as a store underperformance trigger or a strategic decision to exit a market.
• Flag short-term lease elections for quarterly review: if a lease is renewed, the exemption may no longer apply.

Mistake 3: Discount Rate Errors (IBR vs. Risk-Free Rate)

The incremental borrowing rate (IBR) is the single most audited input in ASC 842 calculations, and the errors are systematic, not random.

Under KPMG's lease accounting handbook, the IBR must reflect the rate the lessee would pay to borrow on a collateralized basis over a similar term, in a similar economic environment, and for a similar amount as the lease payments. The most common errors:

Private companies and not-for-profits may elect the risk-free rate practical expedient under ASC 842-20-30-3, but the election must be made by class and documented. The SEC has flagged IBR methodology in comment letters to public companies, specifically requesting disclosure of the basis and methodology for determining the rate.

The fix:

• Build an IBR matrix by lease term bucket and currency at each reporting date. Refresh it at least annually and at each modification.
• If electing the risk-free rate, document the class-level election explicitly in your accounting policy and apply it to every lease in that class.
• Retain the IBR support file (credit analysis, comparable borrowing rates, term adjustments) as an audit-ready workpaper.

Mistake 4: Lease Modification and Remeasurement Failures

Lease modifications are where ongoing compliance breaks down most visibly. The accounting team is often the last to know a lease was modified.

Under EY's lease accounting guide, a modification that grants the lessee an additional right of use not included in the original lease, and is priced commensurate with the standalone price, is treated as a separate new lease. All other modifications require remeasurement of the lease liability using a revised discount rate as of the modification date. The most common error: carrying the original IBR forward through a modification rather than redetermining it.

Variable lease payments linked to an index or rate (e.g., CPI-linked rent escalations) must also be remeasured when the lease liability is remeasured. A separate error is including variable payments not based on an index or rate, such as percentage-of-sales rents, in the lease liability. Under ASC 842-20-30-5, only index- or rate-based variable payments are included in the initial and remeasured liability.

Why it happens: Real estate, procurement, and operations teams execute lease amendments without notifying accounting. There is no event-notification workflow.

The fix:

1. Implement a lease event notification policy: any contract amendment, renewal exercise, early termination, or rent concession triggers an accounting review within a defined window (e.g., five business days).
2. Build remeasurement checklists that explicitly require a new IBR determination at the modification date.
3. Distinguish index-based variable payments (include in liability) from performance-based variable payments (exclude) in your lease abstracts.

Mistake 5: ASU 2023-01 Leasehold Improvement Errors (New for 2026)

This is the error that the top-ranking articles on this topic have entirely missed. ASU 2023-01, effective for fiscal years beginning after December 15, 2023, changed the amortization rule for leasehold improvements in common-control arrangements for ALL entities, public and private.

Before ASU 2023-01, a lessee amortized leasehold improvements over the shorter of the improvement's useful life or the lease term. Under the new rule, leasehold improvements associated with common-control leases are amortized over the useful life of the improvement to the common control group, regardless of the lease term. When the lessee no longer controls the use of the underlying asset, the leasehold improvements must be accounted for as a transfer between entities under common control through an adjustment to equity (or net assets for not-for-profit entities).

As FASB staff noted in the ASU 2023-01 press release: "The practical expedient for common control arrangements is a welcome simplification for private companies, but the leasehold improvement change applies to everyone, public companies included, and many have not updated their accounting policies to reflect the new amortization requirement."

Who is affected:

• All entities with leasehold improvements on common-control leases (e.g., a subsidiary leasing space from a parent or sister entity)
• Private entities only for the practical expedient on using written terms to determine lease existence and classification

The fix:

• Identify every lease in your portfolio where the lessor is an entity under common control.
• Update your accounting policy to reflect the new amortization period (useful life to the common control group, not the lease term).
• Determine whether to adopt prospectively (new improvements only) or retrospectively, and document the transition method chosen.
• For public companies: confirm your auditors have reviewed the updated policy, since many audit teams are also unfamiliar with this change.

Mistake 6: Tenant Improvement Allowance (TIA) Accounting Errors

TIAs are a persistent source of ASC 840-to-ASC 842 legacy errors. Under ASC 840, TIAs were sometimes recorded as deferred rent liabilities. Under ASC 842, a TIA is a lease incentive that reduces the initial measurement of the ROU asset.

Under ASC 842-20-30-5, if the TIA has not yet been received at lease commencement, it is still included in the lease incentive calculation as a lease incentive receivable, reducing the ROU asset. The two most common errors:

1. Recording the TIA as a deferred rent liability (the ASC 840 treatment), which overstates both assets and liabilities.
2. Excluding an unpaid TIA from the ROU asset calculation at commencement, which overstates the ROU asset.

The fix: At lease commencement, confirm whether any TIA is receivable but unpaid. Include it in the lease incentive offset to the ROU asset regardless of receipt timing. Purge any remaining deferred rent liability accounts from the ASC 840 era.

Mistake 7: ROU Asset Impairment Oversight

ROU assets are long-lived assets subject to impairment testing under ASC 360-10-35, and they are routinely excluded from the impairment workflow because they do not sit in the fixed-asset register.

The impairment test for operating lease ROU assets follows the same recoverability and fair value framework as other long-lived assets. Triggering events include store closures, sublease decisions, and significant declines in business performance. The error is treating ROU assets as off-balance-sheet items for impairment purposes, or failing to include them in the asset group tested for impairment.

The fix: Add ROU assets to the long-lived asset impairment trigger checklist. When a triggering event occurs (store closure decision, sublease executed, significant revenue decline in a location), include the ROU asset in the asset group and run the ASC 360 recoverability test.

Mistake 8: Inadequate Disclosures (Where the SEC Is Actually Catching Companies)

ASC 842-20-50 requires a specific set of quantitative and qualitative disclosures, and the SEC's Division of Corporation Finance has issued comment letters identifying exactly where companies fall short.

Required disclosures include:

• Nature of leases (qualitative)
• Maturity analysis of lease liabilities
• Tabular disclosure of lease costs (operating, finance, short-term, variable, sublease income)
• Supplemental cash flow information
• Weighted-average remaining lease term and discount rate
• Qualitative and quantitative information about options, variable payments, and residual value guarantees

The SEC's most common comment letter themes on ASC 842:

Why it happens: Finance teams complete the quantitative tables and treat the qualitative sections as a compliance checkbox. The qualitative disclosures are then identical year over year, regardless of portfolio changes.

The fix:

• Draft qualitative disclosures that describe your actual portfolio: asset classes, typical lease terms, renewal option practices, and variable payment structures.
• Reconcile the maturity analysis to the balance sheet lease liability before filing. This is a mechanical check that should be part of the disclosure review.
• Describe the IBR methodology in enough detail that a reader could understand how rates were determined for different asset classes and terms.

Finance vs. Operating Lease Classification: The Income Statement Consequence

Misclassification has real P&L consequences, not just balance sheet ones. Under ASC 842-10-25-2, a lease is classified as a finance lease if it meets any one of five criteria at commencement:

1. Transfer of ownership to the lessee
2. Purchase option reasonably certain to be exercised
3. Lease term is for the "major part" of the remaining economic life (75% is the legacy ASC 840 reference point, though not mandated)
4. Present value of lease payments equals or exceeds "substantially all" of the fair value (90% is the legacy reference point, not mandated)
5. Specialized asset with no alternative use to the lessor

Finance leases front-load expense: interest accretes on the liability and the ROU asset amortizes separately, producing higher total expense in early periods. Operating leases recognize straight-line rent expense. EBITDA is also affected differently: finance lease interest and amortization sit below EBITDA; operating lease expense does not. A misclassification that flips a finance lease to operating can materially inflate reported EBITDA.

Sale-Leaseback Transactions: A High-Dollar Error Area

Sale-leaseback errors are common and high-stakes, particularly for real estate-heavy companies using sale-leasebacks as financing tools.

Under ASC 842-40, the first question is whether the transfer of the asset qualifies as a sale under ASC 606. If the transfer does not qualify as a sale (for example, because of a repurchase option that gives the seller-lessee the right to reacquire the asset), the transaction must be accounted for as a financing arrangement, not a sale-leaseback. The gain on sale is deferred. The common error is treating the transaction as a completed sale and recognizing the gain immediately, without evaluating the ASC 606 sale criteria.

The fix: Before closing a sale-leaseback, route the contract through accounting to evaluate the ASC 606 sale criteria, specifically whether any repurchase option or other provision prevents sale recognition.

A Note on Sublease Accounting

When a lessee subleases the leased asset, it becomes an intermediate lessor and must classify the sublease by reference to the ROU asset, not the underlying asset. This often results in operating lease classification for the sublease even when the economics resemble a finance lease. The common error is classifying the sublease by reference to the underlying asset, which produces incorrect income statement treatment for the intermediate lessor.

Practical Remediation Steps for 2026

If you are preparing for an audit or responding to a prior-year finding, work through these steps in sequence:

1. Run a population completeness check. Pull all service, outsourcing, IT, and logistics contracts above your materiality threshold and re-evaluate for embedded leases. Document the analysis.
2. Audit your IBR documentation. For each lease, confirm the IBR is collateralized, term-specific, and currency-specific. Rebuild the support file if it does not meet that standard.
3. Review all modifications in the past 12 months. Confirm each triggered a remeasurement with a revised IBR. Check that CPI-linked payments were updated at remeasurement.
4. Update your accounting policy for ASU 2023-01. Identify common-control leases, apply the new leasehold improvement amortization rule, and document the transition method.
5. Test your disclosure package against the SEC comment letter checklist above. Reconcile the maturity analysis to the balance sheet. Replace boilerplate qualitative language with portfolio-specific description.
6. Add ROU assets to your impairment trigger checklist. Confirm they are included in the relevant asset groups for ASC 360 testing.

FAQ

Is ASC 842 still relevant in 2026?

Yes. All US GAAP entities have been required to apply ASC 842 for at least three to four fiscal years, but errors persist because lease portfolios change continuously. ASU 2023-01, effective for fiscal years beginning after December 15, 2023, introduced new requirements for leasehold improvements in common-control arrangements that apply to public and private companies alike. The standard is actively enforced through SEC comment letters and PCAOB inspections.

What discount rate should lessees use first under ASC 842?

Lessees should use the rate implicit in the lease if it is readily determinable. If not, they use the IBR: the collateralized rate the lessee would pay to borrow a similar amount over a similar term in a similar economic environment. Private companies and not-for-profits may elect the risk-free rate as a practical expedient under ASC 842-20-30-3, but the election must be made by class of underlying asset and applied consistently across all leases in that class.

What does ASU 2023-01 change for public companies?

ASU 2023-01 changed the amortization rule for leasehold improvements on common-control leases for all entities, including public companies. Improvements must now be amortized over the useful life of the improvement to the common control group, not the shorter of the useful life or the lease term. When the lessee no longer controls the underlying asset, the remaining improvement balance is transferred through equity, not expensed. Many public companies have not updated their accounting policies to reflect this.

When does a lease modification require remeasurement?

All modifications except those that qualify as separate new leases require remeasurement of the lease liability using a revised discount rate as of the modification date. A modification is a separate new lease only if it grants an additional right of use not in the original lease and is priced commensurate with the standalone price. Every other change, including term extensions, rent reductions, and partial terminations, triggers remeasurement.

What are the key ASC 842 disclosure requirements the SEC focuses on?

The SEC has flagged four areas in comment letters: insufficient disaggregation of lease costs (variable, short-term, and sublease income must be shown separately); inadequate description of IBR methodology; maturity analysis that does not reconcile to the balance sheet lease liability; and qualitative disclosures that are generic rather than entity-specific. All are required under ASC 842-20-50.

How do I know if a contract contains an embedded lease?

Apply the two-part test from ASC 842-10-15-9: does the customer have the right to obtain substantially all of the economic benefits from use of an identified asset, and the right to direct how and for what purpose that asset is used throughout the period of use? If yes to both, the contract contains a lease regardless of how it is labeled. Dedicated assets, whether servers, manufacturing lines, or vehicles, are the highest-risk category.