Rating Notching

Rating agencies rarely assign a single grade to a company or government. Instead, they anchor on an issuer rating—a baseline that reflects overall creditworthiness—and then apply rating notching, systematically adjusting individual debt instruments up or down by one or more notches based on seniority, collateral, and structuring. A borrower with an issuer rating of BBB might have secured bonds rated BBB+ and subordinated notes rated BB−, all issued by the same legal entity.

Issuer rating as the anchor

Every major non-sovereign borrower receives an issuer rating (also called the corporate family rating or parent rating). This is a holistic assessment of default risk: the company’s industry position, cash generation, leverage, asset quality, management, and macroeconomic sensitivity. A utilities company in a stable regulatory regime might receive an A issuer rating; a cyclical manufacturer might be BBB.

Once the issuer rating is set, each piece of debt issued gets its own instrument rating—one that reflects the specific claim: its legal position in the waterfall, whether it is backed by collateral, and whether it is guaranteed by a stronger party.

The mechanics of notching

Senior secured debt typically receives an uplift of +1 or +2 notches. If the issuer is rated BBB, senior secured bonds might be BBB+ or A−. The logic is clear: in insolvency, secured creditors recover before unsecured ones. A junior lender holding a first mortgage on industrial equipment knows it can force a sale and retrieve principal; an unsecured bondholder stands behind banks, suppliers, and employees.

Senior unsecured debt usually sits at or near the issuer rating—perhaps one notch lower if the borrower has large secured bank debt that will consume liquidation proceeds. A manufacturing company with heavy secured bank facilities might have an issuer rating of A− but senior unsecured bonds rated BBB+.

Subordinated and junior unsecured debt get notched down—typically −1 to −3 notches. A company rated BBB− issuer might have senior unsecured at BBB− and subordinated unsecured at B+. In a bankruptcy, subordinated debt recovers only after all senior claims are satisfied, and recovery rates are often 5–30 cents on the dollar.

Guarantees and cross-collateralization

A guarantee from a stronger party can lift a rating. If a weak subsidiary is 100% guaranteed by an investment-grade parent, the subsidiary’s bonds may be rated at or near the parent’s issuer rating. Agencies closely scrutinize guarantees for legal enforceability, however; a weak or contingent guarantee gets little or no notching benefit.

Intra-group cross-defaults and cross-collateralization clauses also matter. A holding company with strong operating subsidiaries might have a lower issuer rating than those subsidiaries, but if losses in one subsidiary trigger default across the entire group, subordinated debt at the holding level loses recovery value. Agencies will notch accordingly.

Regulatory and market effects

The Securities and Exchange Commission and banking regulators enforce portfolio rules on investment-grade-only purchases. These rules typically refer to the instrument rating, not the issuer rating. A senior secured bond from a BB issuer, if notched to BBB−, qualifies as investment-grade; the same issuer’s subordinated debt at B+ does not, even though both are issued by the identical legal entity. This creates a profitable arbitrage for sophisticated investors and structures.

Investment-grade mandates in pension funds, insurance companies, and certain mutual funds thus create artificial demand for notched-up senior secured tranches, widening the spread between them and unsecured or subordinated bonds from the same issuer. During credit crunches, when investors flee subordinated debt, these spreads can blow out to extremes—a 5+ notch gap translating to 500–1000 basis points of yield difference.

Formulaic vs. discretionary notching

Most major agencies (S&P, Moody’s, Fitch) publish semi-formulaic notching methodologies—tables that assign typical uplifts for senior secured, senior unsecured, and subordinated. A rating analyst may deviate for idiosyncratic factors: an issuer with no debt covenant protections, or with aggressive off-balance-sheet financing, might receive a harsher notch down. A company with exceptionally stable, ring-fenced cash flows might receive an uplift.

Regional or smaller agencies sometimes apply more discretionary, bespoke adjustments, particularly for complex financial structures or emerging-market borrowers where recovery assumptions are harder to quantify.

Notching in structured products

Securitizations and credit events involve extreme notching. A mortgage-backed security tranche rated AAA might be backed by loans from issuers rated only BBB. The notching here works inversely: the structure itself—subordination of lower tranches, overcollateralisation, and credit enhancement—pushes the senior tranche to the top of the scale.

Similarly, a business development company with portfolio companies averaging B rating might issue BBB senior notes because the portfolio’s diversity and the leverage discipline reduce single-issuer risk. This form of notching relies on statistical assumptions about correlation and recovery that proved dangerous in the 2008 crisis.

Criticism and consistency

Notching methodologies are public but imperfectly consistent across issuers and geographies. A subordinated bond in one company might be notched down 2 notches; an identical instrument at another company, 3. This inconsistency stems from issuer-specific factors—but also from agency competitive pressure and the use of notching to fine-tune ratings toward investment-grade status for deals that agencies want to rate higher.

Some argue that the notching of secured debt is too generous, inflating the effective ratings of secured creditors. Others contend that unsolicited ratings (issued without issuer cooperation) apply more conservative notches, potentially disadvantaging companies that request ratings. Both criticism and the practice itself persist.

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