What is Original Issue Discount, and When Can It Affect a Convertible Note Financing?

Original issue discount can create an immediate accounting and diligence problem when a convertible note's face amount exceeds the proceeds received, including when value is allocated to detachable warrants. Under U.S. GAAP, OID reduces the note's initial carrying value and must be amortized to interest expense using the effective interest method. If OID is missed, the note balance, interest expense, tax schedule, and conversion accounting can all be misstated before an institutional raise.

Key point: OID is a discount embedded in the note's structure. It is separate from any fee paid at closing, and it requires its own accounting treatment.

What OID Is and When It Arises on a Convertible Note

OID is the difference between a note's stated face amount and the amount the issuer actually receives at closing. If a company issues a $1,000,000 convertible note but receives only $950,000 in proceeds, the $50,000 difference is OID.

On a convertible note, OID can arise in three ways.

Proceeds Below Face Amount

The simplest case: the investor pays less than the face amount. The gap between what was paid and what will be repaid is OID from day one.

Warrants Issued with the Note

This is the most commonly missed trigger. When a company issues detachable warrants alongside a convertible note, the proceeds must be allocated between the note and the warrants based on their relative fair values under ASC 470-20. The portion allocated to the warrants reduces the carrying value of the note below its face amount. That difference is OID, even if the investor paid the full face amount in cash.

Example: A company issues a $500,000 convertible note with detachable warrants. The warrants are valued at $40,000. The note is initially recorded at $460,000. The $40,000 is OID.

Beneficial Conversion Features (Pre-2022)

Before ASU 2020-06 took effect, a convertible note with a conversion price below the fair value of the underlying stock at issuance created a beneficial conversion feature (BCF). The BCF was recorded as a discount on the note, which was also treated as OID for amortization purposes. ASU 2020-06 eliminated BCF accounting for most entities, but notes issued before the adoption date still carry this history and require careful review.

Summary: OID Triggers on a Convertible Note

How OID Is Recorded and Amortized Under U.S. GAAP

Under ASC 835-30, OID is recorded as a contra-liability that reduces the note's initial carrying value on the balance sheet. The note does not appear at face value. It appears at face value minus the unamortized OID balance.

The Effective Interest Method

OID is amortized using the effective interest method. Each period, the company calculates interest expense using the note's effective interest rate, which is higher than the stated coupon because it reflects the original discount. The difference between the effective interest expense and the cash interest paid is the OID amortization for that period.

Over time, the unamortized OID balance declines to zero, and the note's carrying value increases to its face amount by the maturity date.

Balance Sheet Presentation

A properly presented convertible note on the balance sheet shows three lines:

• Face amount: The contractual repayment obligation
• Less: unamortized OID: The remaining discount not yet amortized
• Less: unamortized debt issuance costs: The remaining issuance costs (tracked separately)
• Net carrying value: What appears as the liability

What Happens at Conversion or Early Repayment

If the note converts to equity before maturity, any unamortized OID balance is written off immediately to interest expense at the conversion date. It does not transfer to equity. The same applies to early cash repayment: the remaining OID is accelerated into interest expense on the repayment date.

This acceleration can create a large, unexpected interest expense charge in the period a round closes. Finance teams that have not tracked OID separately often discover this problem when the auditor asks for the conversion journal entry.

OID Versus Debt Issuance Costs: How They Interact on the Same Note

OID and debt issuance costs are different things. Both reduce the carrying value of a note. Both amortize through interest expense. But they have different origins and must be tracked separately.

The carrying value of a note with both items is: face amount minus unamortized OID minus unamortized debt issuance costs.

Conflating the two is a common error. A company that lumps issuance costs into the OID balance will misstate both line items. When an auditor or diligence team reconstructs the note schedule, they will separate the two and recalculate the effective interest rate. If the numbers do not reconcile to the original note documentation and warrant valuation, it creates a diligence finding.

For a detailed treatment of how debt issuance costs are recorded and amortized on their own, see the companion article on debt issuance costs on a convertible note.

Tax Treatment of OID: Why It Matters Beyond the Balance Sheet

OID has tax consequences that run independently of the GAAP accounting. Under IRC Section 1272, OID accrues as income to the holder and as a deductible interest expense to the issuer on an economic accrual basis, not on a cash basis.

This means the holder must report OID income each year even if no cash interest is paid. It also means the issuer can deduct OID amortization as interest expense each year, even before any cash leaves the company.

Why the Tax Basis Must Be Tracked Separately

The GAAP amortization schedule and the tax amortization schedule are calculated using different methods. GAAP uses the effective interest method. Tax uses a constant-yield method under IRC Section 1272, which may produce different annual accrual amounts.

A company that relies only on its GAAP schedule to support its tax return will produce a mismatch. That mismatch becomes a finding when a tax advisor or diligence team reviews the company's deferred tax positions.

The practical step: Maintain a separate OID amortization schedule for tax purposes, reconciled annually to the GAAP schedule and to the note's original issue price documentation.

Founders approaching an institutional raise should confirm that their tax advisor has reviewed the OID position on every outstanding note before the data room is assembled.

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How Auditors and Diligence Teams Flag OID Errors

OID errors surface in predictable places. Auditors and institutional diligence teams follow a standard review sequence for convertible notes, and each step is a checkpoint where a missing or misapplied OID treatment becomes visible.

The Three Most Common Errors

1. Ignoring OID when warrants are issued with the note. A company issues a convertible note with warrants, records the full proceeds as the note's carrying value, and never allocates any amount to the warrants. The result is an overstated note balance and understated interest expense for every period the note was outstanding. When the auditor requests the warrant valuation at issuance, there is none.

2. Conflating OID with debt issuance costs. The company records all closing-related items, including the warrant-allocated OID, in a single "debt discount" line without separating OID from issuance costs. The effective interest rate calculation is wrong. The tax schedule does not exist. The two balances cannot be reconciled to the note documentation.

3. Failing to accelerate unamortized OID at conversion. The note converts to equity and the company records only the principal as the conversion amount. The unamortized OID is left on the balance sheet. This overstates the equity recorded at conversion and understates interest expense for the period.

What Diligence Teams Request

When an institutional investor or their accounting advisor reviews a company's notes payable, they typically request:

• The original note agreement and any warrant agreements
• A warrant valuation at the issuance date
• The OID amortization schedule, separate from the issuance cost schedule
• The effective interest rate calculation
• The tax OID schedule and reconciliation to the GAAP schedule
• Conversion journal entries with the OID write-off shown explicitly

A company that cannot produce these items on short notice signals that the accounting was not done correctly the first time. That signal is hard to walk back during diligence, which is why the 10 Mistakes That Kill Your Institutional Raise article is a useful pre-check for teams heading into a raise.

What This Looks Like in Practice

A growth-stage software company issued two convertible notes during its seed round. Each note came with detachable warrants. The company recorded the full proceeds as the note balance and treated the warrants as a separate equity item with no allocation against the note. No OID was recognized.

Eighteen months later, the company began preparing for a Series B. The lead investor's accounting team requested a full note schedule as part of financial diligence. When the warrants were valued at the original issuance dates, the combined OID across both notes was material. The company had to restate two years of interest expense, adjust the carrying value of the notes, and rebuild the tax schedule from scratch.

The restatement delayed the diligence process by six weeks and required the company to engage a separate accounting firm to document the remediation. The notes had already converted by then, which meant the unamortized OID at conversion had also been missed. A second adjustment was required for the equity accounts.

The structural issue was not complex. A warrant allocation at issuance, a separate OID amortization schedule, and a tax reconciliation would have taken a few hours to set up correctly. The cost of fixing it two years later was measured in weeks and professional fees.

This pattern repeats across early-stage companies that issued notes with warrants and did not have a technical accounting review at the time of issuance. The convertible note overhang problem is well documented. The OID layer inside it is less often discussed, but it is just as discoverable. That is why the 10 Mistakes That Kill Your Institutional Raise guide is useful before diligence starts.

Get Your Accounting Right Before the Raise Starts

OID errors are fixable. They are far cheaper to fix before an institutional process begins than during one. If your company has issued convertible notes with warrants, discounted proceeds, or pre-2022 BCFs, the time to review the accounting is now.

The checklist is straightforward:

• Identify every convertible note with a warrant, a proceeds gap, or a pre-2022 BCF
• Obtain or reconstruct the warrant valuation at the original issuance date
• Calculate the OID amount and build a separate amortization schedule using the effective interest method
• Build a separate tax OID schedule under IRC Section 1272 and reconcile it to the GAAP schedule
• Confirm that any converted notes had their unamortized OID accelerated to interest expense at conversion
• Confirm that OID and debt issuance costs are tracked in separate line items

A capital raise that stalls in diligence over a correctable accounting issue is one of the more avoidable outcomes in a raise process. The Capital Raise Pre-Flight is IRC Partners' fixed-fee diagnostic that scores a raise against the same twelve institutional gates a deal must clear before IRC Partners takes it into a strategic partnership. It is a fixed-fee, 20 to 30 page written diagnostic report delivered in ten business days, built for founders and real estate sponsors raising five million dollars or more who want to know exactly where their deal breaks before an investor finds it.

Frequently Asked Questions

What is original issue discount on a convertible note?

Original issue discount is the difference between a convertible note's face amount and the proceeds the issuer actually receives. It arises when an investor pays less than face value, or when a portion of the proceeds is allocated to warrants or other features issued alongside the note. OID is recorded as a discount on the note and amortized to interest expense over the note's life using the effective interest method under ASC 835-30.

Does issuing warrants with a convertible note always create OID?

Yes, if the warrants have any fair value at issuance. When detachable warrants are issued with a convertible note, the total proceeds must be allocated between the note and the warrants based on their relative fair values under ASC 470-20. The amount allocated to the warrants reduces the note's carrying value below its face amount, and that difference is OID. This applies even when the investor pays the full face amount in cash.

How is OID different from debt issuance costs?

OID is a structural feature that arises from the note's economics: a proceeds gap or a warrant allocation. Debt issuance costs are transaction costs paid to third parties to complete the financing, such as legal fees and placement fees. Both reduce the carrying value of the note and both amortize through interest expense using the effective interest method. They must be tracked in separate line items and cannot be combined into a single discount balance.

What happens to unamortized OID when a convertible note converts to equity?

Any unamortized OID balance is written off immediately to interest expense on the conversion date. It does not carry over to the equity accounts. A company that fails to record this acceleration will overstate the equity issued at conversion and understate interest expense for that period. This is one of the most commonly missed steps when a note converts during a priced round.

How does OID affect taxes?

Under IRC Section 1272, OID accrues as taxable income to the note holder each year and as a deductible interest expense to the issuer each year, regardless of whether any cash is paid. The tax amortization schedule uses a constant-yield method that may differ from the GAAP effective interest schedule. Both schedules must be maintained separately and reconciled annually. A company that uses only its GAAP schedule to support its tax return risks a mismatch in its deferred tax positions.

Why do institutional diligence teams specifically look for OID?

Institutional diligence teams review every convertible note and request the original note agreement, any warrant agreements, and a warrant valuation at the issuance date. If OID was not recognized, the carrying value of the note is overstated, the effective interest rate is wrong, and there is no tax schedule to produce. Each of those gaps is a separate finding. Together they signal that the company's technical accounting was not reviewed at the time of issuance, which raises broader questions about financial statement reliability.

Can OID from a pre-2022 beneficial conversion feature still affect a company today?

Yes. Notes issued before the adoption of ASU 2020-06 that had a beneficial conversion feature carry OID from that BCF in their amortization history. If those notes are still outstanding, the unamortized BCF-related OID must continue to be amortized. If those notes have already converted, the conversion accounting must be reviewed to confirm the unamortized OID was accelerated to interest expense at the conversion date. Notes issued after a company adopted ASU 2020-06 are not subject to BCF accounting.

Continue reading this series:

• What happens to non-participating preferred stockholders in a pay-to-play bridge round
• What Happens to Your Warrants at Series B
• How should a startup structure bridge financing if a major customer contract is expected to be the next financing catalyst

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