Commercial Paper Explained: How Companies Issue Short-Term Debt

TL;DR: Commercial paper is an unsecured, short-term promissory note issued by corporations and financial institutions to fund immediate obligations like payroll and inventory. By keeping maturities under 270 days, issuers qualify for an exemption from formal SEC registration under Section 3(a)(3) of the Securities Act of 1933, securing cash at rates significantly lower than bank loans. However, because commercial paper relies on continually rolling over maturing debt in the money markets, any credit downgrade or market panic creates immediate refinancing risk.

What Is Commercial Paper and Where Does It Fit?

When a corporation finances a ten-year capital project, it issues long-term bonds. But when that same company needs $50 million for 45 days to bridge payroll or finance seasonal inventory before customer receivables clear, issuing long-term debt is inefficient. Drawing on a bank line of credit is an option, but bank facilities carry commitment fees, compensating balances, and higher borrowing spreads.

Commercial paper (CP) provides an alternative. It is an unsecured corporate IOU issued directly to institutional investors. In capital-markets architecture, commercial paper sits in the money market—the global marketplace for short-term, liquid credit instruments alongside Treasury bills and repurchase agreements (repo).

Unlike standard corporate bonds, commercial paper does not require an elaborate trust indenture or restrictive affirmative and negative debt covenants. It is a negotiable promissory note sold to money market funds, corporate treasurers, and insurance liquidity pools seeking a yield pick-up over risk-free government bills.

The 270-Day Rule: Section 3(a)(3) Exemption

Commercial paper maturities range from 1 to 270 days, but the vast majority matures within 30 to 50 days, and virtually none exceeds 270 days. This limit exists for a specific legal reason.

Under Section 3(a)(3) of the Securities Act of 1933, short-term notes arising from current commercial transactions with maturities not exceeding nine months (270 days) are exempt from filing an SEC registration statement. This statutory exemption allows qualified issuers to raise tens of millions of dollars in institutional cash within hours, avoiding legal drafting costs, registration delays, and ongoing public prospectus disclosures.

The Three Segments of the Commercial Paper Market

According to the Federal Reserve Board’s Commercial Paper Summary, total U.S. commercial paper outstanding stood at $1,436.9 billion as of September 9, 2026. The market operates across three primary sectors:

• Financial Commercial Paper ($601.8 Billion, 41.9%): Issued by commercial banks, bank holding companies, and financial intermediaries (including captive auto lenders). These firms issue paper continuously to fund bridge facilities, consumer loans, and commercial lending. Foreign banking institutions account for $348.6 billion of this segment.
• Asset-Backed Commercial Paper / ABCP ($498.1 Billion, 34.7%): Issued by bankruptcy-remote Special Purpose Vehicles (SPVs) rather than operating companies. The SPV purchases credit card receivables, auto loans, or trade receivables from sponsors, pledging those cash flows as collateral for the notes.
• Nonfinancial Commercial Paper ($337.0 Billion, 23.5%): Issued by industrial corporations, retailers, utilities, and tech giants (such as Apple, Microsoft, and Walmart) to smooth seasonal working capital and tax disbursements. Domestic U.S. corporations account for $266.8 billion of this total.

How Commercial Paper Is Priced: The Discount Math

Commercial paper does not pay periodic coupon interest. Like Treasury bills, it is issued at a discount to face value and redeemed at par upon maturity. The spread between the purchase price and face value represents the lender’s interest return.

Dealers quote rates on a Bank Discount Yield (y_d) basis using a 360-day commercial year:

From this quoted discount rate, the dollar purchase price ($P$) paid by the buyer is calculated as:

Because the discount yield divides the dollar gain by face value rather than actual cash invested, it understates true investor yield. Financial managers convert discount yields into a Money Market Yield (y_mm) or a 365-day Bond Equivalent Yield (BEY):

A Worked Issuance Example

Consider an investment-grade logistics firm issuing $50,000,000 face value of 60-day commercial paper quoted at a discount rate of 3.80%.

1. Dollar Discount: $50,000,000 × 0.0380 × (60 / 360) = $316,666.67
2. Net Issuance Proceeds: $50,000,000 – $316,666.67 = $49,683,333.33 (the cash wired to the firm today).
3. Money Market Yield: ($316,666.67 / $49,683,333.33) × (360 / 60) = 3.824%
4. Bond Equivalent Yield (365-day basis): ($316,666.67 / $49,683,333.33) × (365 / 60) = 3.877%

In 60 days, the company owes $50,000,000. In regular market conditions, it pays this principal by issuing a new 60-day commercial paper tranche—a routine operational rhythm called rolling the debt.

Credit Rating Tiers and the “Tier 2 Cliff”

Because commercial paper is unsecured, buyers rely heavily on specialized short-term credit rating scales established by Standard & Poor’s, Moody’s, and Fitch:

• Tier 1 (Prime-1 / A-1 / F1): The highest short-term credit quality. Issued by corporations with senior AA or strong A long-term ratings.
• Tier 2 (Prime-2 / A-2 / F2): High credit quality, but somewhat more vulnerable to economic headwinds. Typically aligned with BBB long-term corporate credit.
• Tier 3 (Prime-3 / A-3 / F3): Marginally acceptable credit capacity, but facing elevated vulnerability to near-term financing shocks.

The primary buyers of commercial paper are prime money market funds regulated under SEC Rule 2a-7. Rule 2a-7 strictly limits portfolio risk: funds are capped on how much Tier 2 paper they may hold (historically limited to no more than 3% to 5% of total assets, with no single Tier 2 issuer exceeding 0.5%), and they are barred from purchasing Tier 3 paper.

This creates the “Tier 2 cliff.” When a borrower’s rating falls from Tier 1 to Tier 2, up to 90% of prime money market buyers are forced to exit. The remaining buyers demand higher borrowing spreads to absorb the credit risk.

Federal Reserve H.15 data demonstrates this spread clearly. As of September 11, 2026, 30-day AA commercial paper traded at 3.77%, while 30-day A2/P2 paper traded at 4.00%—a 23 basis point credit premium. At 90 days, the spread expands to 27 basis points (3.86% vs. 4.13%). In periods of financial stress, this tier spread can widen past 150 basis points.

The Liquidity Backstop: Backup Lines of Credit

Because market conditions can turn rapidly, rating agencies mandate that commercial paper issuers maintain committed bank revolving credit facilities covering up to 100% of their outstanding paper. If money market investors refuse to purchase new notes, the company draws down its committed bank facility to redeem maturing debt, preventing technical default.

Rollover Risk and the 2008 Lehman Brothers Shock

The core structural vulnerability of commercial paper is rollover risk. Because notes mature within weeks, borrowers must continuously find replacement buyers. If buyers withdraw, the issuer faces an immediate cash run.

The clearest historical illustration occurred in September 2008:

• The Reserve Primary Fund, a $62 billion money market fund, held $785 million of unsecured commercial paper issued by Lehman Brothers.
• When Lehman declared Chapter 11 bankruptcy on September 15, 2008, its commercial paper lost its value.
• The loss forced the Reserve Primary Fund’s net asset value (NAV) down to $0.97 per share on September 16. The fund had “broken the buck,” breaching the $1.00 stable NAV standard.
• Institutional investors panicked, triggering a massive run across money market mutual funds. Within days, funds hoarded cash and ceased buying commercial paper.
• Corporations with impeccable operating balance sheets suddenly could not roll over short-term paper to fund day-to-day payroll.

To halt the collapse, the Federal Reserve established the emergency Commercial Paper Funding Facility (CPFF), stepping in as a direct buyer of 3-month commercial paper. The Fed revived the CPFF during the March 2020 liquidity shock, proving that commercial paper liquidity is essential to overall financial stability.

Common Mistakes to Avoid

• Equating commercial paper with corporate bonds: Commercial paper is short-term (under 270 days), sold at a discount, exempt from SEC registration, and designed for operational working capital rather than long-term capital investments.
• Assuming commercial paper is default-free: Although issuers are high grade, commercial paper carries corporate credit risk and rollover vulnerability. Unlike Treasury bills, it is not backed by sovereign taxation authority.
• Overlooking the discount yield distortion: Quoted discount yields divide by face value, understating true returns. Always convert to money market yield or bond equivalent yield to make accurate comparisons.
• Assuming issuance capacity is unlimited: Companies cannot issue commercial paper beyond what their committed bank backup lines and rating tier capacity can support.

Related Concepts: What to Learn Next

Commercial paper functions alongside broader money-market and fixed-income structures. To deepen your understanding of corporate debt and rate dynamics, review these guides:

• Repo and Reverse Repo Explained: The Plumbing of Short-Term Finance — Explore secured short-term lending against Treasury collateral.
• Debt Covenants Explained: Affirmative, Negative, and Cov-Lite — Understand the terms lenders enforce on bank revolving credit facilities.
• The 4 Yield Curve Shifts: Bull vs. Bear Steepeners & Flatteners — How rate moves across money markets and benchmark bonds signal economic transitions.

Sources

• Federal Reserve Board: Commercial Paper Rates and Outstanding Summary (Statistical Release)
• Federal Reserve: Commercial Paper Market Overview and Calculation Methodology
• Federal Reserve Board: Commercial Paper Funding Facility (CPFF) Policy Archive
• U.S. Securities and Exchange Commission: Money Market Fund Reforms (Rule 2a-7 Overview)

Disclosure: This article is for informational purposes only and is not investment advice.