Under FRS 102 Section 20, lessees use the obtainable borrowing rate (OBR) to discount future lease payments when the interest rate implicit in the lease cannot be readily determined. LOIS defines the OBR as the rate a lessee would pay to borrow, over a similar term, an amount equal to the total undiscounted lease payments. In practice, for most UK and Irish organisations, this means the rate a bank would charge on a loan of comparable term and size. It is simpler to document than the IFRS 16 incremental borrowing rate (IBR), and deliberately so.
This post covers how the OBR works, how to determine it, what auditors look for, and what happens when the rate is wrong. For a broader picture of how lease liabilities are measured and unwound, see What is a lease liability under FRS 102? A plain-English guide. For context on how FRS 102 compares with IFRS 16 more broadly, see FRS 102 vs IFRS 16: key differences finance teams need to know.
Updated June 2026.
The discount rate is the single most consequential input in any FRS 102 lease liability calculation. LOIS uses it to convert a schedule of future lease payments into a present value figure: the number that sits on the balance sheet as the lease liability, with the corresponding right-of-use asset derived from that same figure at commencement. Everything downstream depends on it: the opening liability, the amortisation schedule, the interest charge to profit and loss each period, and the closing balance.
A higher discount rate produces a lower present value. A lower rate produces a higher one. On a long-term lease with material annual payments, even a one-percentage-point difference in the rate can shift the opening balance sheet entry by tens of thousands of pounds. Across a portfolio, it compounds. This is not a peripheral judgement call; it is the foundational number your auditor will test.
Under FRS 102 Section 20, the obtainable borrowing rate is the rate a lessee would pay to borrow, over a similar term and with similar security, an amount equal to the total undiscounted lease payments. LOIS applies it as the practical fallback when the rate implicit in the lease cannot be determined, which is the case for most lessees.
FRS 102 Section 20 sets out a three-step hierarchy for the discount rate. First, use the rate implicit in the lease: the rate that equates the present value of the lease payments to the fair value of the underlying asset. Most lessees cannot determine this rate because they do not have access to the lessor's assumptions about residual value. When that rate cannot be determined, move to the second option: the obtainable borrowing rate.
The OBR is defined in FRS 102 as the rate the lessee would pay to borrow, over a similar term and with similar security, an amount equal to the total undiscounted lease payments. The practical question it answers is: what rate would my bank charge if I borrowed this amount, with this term, today? A current facility rate, a commercial mortgage rate, or a borrowing indication from your bank all satisfy this test when they are documented properly.
If neither the implicit rate nor the OBR can be determined, FRS 102 allows a third fallback: the incremental borrowing rate (IBR) as defined in IFRS 16. In practice, most organisations will not need to reach this stage, because a current bank rate is almost always obtainable. The IBR is the primary fallback under IFRS 16 and requires a more structured calculation approach than the OBR. FRS 102's insertion of the OBR as a middle step is one of the standard's deliberate simplifications, intended to reduce the compliance burden for UK and Irish entities. For a full explanation of how the IBR works under IFRS 16, and how the right-of-use asset is recognised at commencement, see our plain-English IFRS 16 right-of-use asset guide.
FRS 102 vs IFRS 16: what the discount rate rules actually say
| Feature | FRS 102 Section 20 | IFRS 16 |
|---|---|---|
| First choice | Rate implicit in the lease | Rate implicit in the lease |
| Second choice | Obtainable borrowing rate (OBR): rate a lessee can actually obtain from a lender | Incremental borrowing rate (IBR): theoretically constructed, often requires credit spread decomposition |
| Third choice | IBR (as a final fallback) | No further fallback |
| Key practical difference | Point to an actual market rate; no explicit credit spread build-up required | Guidance implies risk-free rate plus credit spread plus adjustments for term, collateral, and currency |
LOIS supports four practical approaches to determining the OBR for UK and Irish organisations working through their first FRS 102 period: use an existing facility rate, request a bank indication, apply a parent-entity rate, or set a rate by lease class. Each is defensible; the right choice depends on how the entity is structured and what evidence is already available.
Four approaches to determining your OBR
The Financial Reporting Council's FRS 102 standard text is available at frc.org.uk and is the primary authority on what the standard requires. The LOIS team works directly from the standard and from practical experience supporting UK and Irish entities through transition, so if your auditor asks for the regulatory basis for your rate selection, the answer is in Section 20.
To understand why the OBR matters, consider a straightforward example: a 10-year lease with annual payments of £100,000. The present value of those payments changes materially depending on the discount rate applied.
| Discount rate | Opening lease liability | Difference vs 5% |
|---|---|---|
| 4% | £811,090 | +£38,916 |
| 5% (base case) | £772,174 | base |
| 6% | £736,009 | -£36,165 |
| 7% | £702,358 | -£69,816 |
Figures illustrative. Based on annual payments of £100,000 over 10 years, discounted at the rate shown. Payments assumed at end of period.
A one-percentage-point error shifts the opening liability by approximately £36,000-£39,000 on a single lease of this size. An organisation with fifty property leases of comparable scale and the wrong rate applied across all of them carries a portfolio-wide misstatement of potentially £1.8 million or more. The right-of-use asset is misstated by the same amount at commencement, affecting depreciation and interest charges through every subsequent period until the lease ends or is modified.
An incorrect OBR under FRS 102 Section 20 creates a cascade of connected errors that compounds through every subsequent period: the opening lease liability is misstated, the right-of-use asset is misstated by the same amount at commencement, and every depreciation and interest charge that flows from those opening figures carries the error forward until the lease ends or a modification triggers a remeasurement.
The practical consequence during audit is straightforward: your auditor will ask for the rate and the basis for selecting it. If you cannot produce a policy document and a rate rationale, you will be asked to obtain one mid-audit, under time pressure. If the rate itself is demonstrably wrong, the liability will need to be restated. For organisations reporting under FRS 102 for the first time in a December 2026 period close (or June 2026, if your balance date is June), this is not a problem to discover at year-end. The FRS 102 amendments are effective for accounting periods beginning on or after 1 January 2026.
There is also a tax dimension. An incorrect opening lease liability affects the split between capital and interest in each period's P&L, which can have tax consequences depending on how your organisation accounts for finance costs. This warrants a conversation with your tax adviser during transition, not after the accounts are filed.
The five rate-related errors LOIS sees most frequently in UK and Irish FRS 102 transitions share a common cause: teams select a number that seems defensible in the moment without documenting why, or apply a rate that was reasonable at commencement to situations where it no longer holds. Each mistake is avoidable with the right policy in place before year-end.
Is the obtainable borrowing rate the same as the incremental borrowing rate?
They are related but not identical. The OBR under FRS 102 is defined as the rate a lessee would pay to borrow an amount equal to the total undiscounted lease payments, over a similar term, pointing to a real, obtainable market rate. The IFRS 16 IBR is conceptually similar but is supported by more prescriptive guidance that implies constructing the rate from a risk-free rate, a credit spread, and adjustments. In practice the two will often be close, but the OBR is specifically designed to be simpler to evidence and document for FRS 102 reporters.
Can I use one discount rate for all my leases?
A lease class approach is acceptable and practical for larger portfolios: apply a single OBR to all leases of a similar type and term. The rate must still reflect what you could actually borrow at for that class of lease. Grouping a 2-year IT lease and a 15-year property lease under the same rate is not defensible; grouping all office leases with a 7-10 year remaining term under one rate is.
Does the OBR change over the life of the lease?
The OBR is locked in at the lease commencement date and does not change simply because market interest rates move. It is, however, reassessed when a lease modification occurs, for example an extension that materially changes the remaining term, or a change in the nature or scope of the lease. At remeasurement, the revised discount rate reflects conditions at the modification date.
What documentation does my auditor need for the OBR?
At minimum: a written policy explaining the basis for rate selection, the rate applied to each lease or lease class, and evidence that the rate is obtainable: a bank facility agreement, a written borrowing indication from your bank, or a documented group lending rate with a rationale for why the entity could access funds on those terms. Auditors working on first FRS 102 periods will look closely at this judgement; prepare the documentation before year-end, not during the audit.
Let LOIS handle rate application and documentation automatically
LOIS stores the obtainable borrowing rate per lease, documents the basis for selection, and applies it consistently across all calculations and remeasurements, so every lease in your portfolio uses the right rate and your auditor can follow the evidence chain without additional work from your team.
See FRS 102 lease accounting software