What it means
A credit rating is an opinion about the likelihood that a borrower will pay what it owes, when it owes it. Agencies publish those opinions on a ladder of letters and notches, and A1 sits fifth from the top of the long-term scale, below Aaa, Aa1, Aa2 and Aa3.
The number after the letter is the notch within the band, so A1 is better than A2, which is better than A3. The rating matters because it sets the price of money.
Many institutional investors operate under mandates that restrict what they may hold by rating, so moving into or out of this band changes the size of the buyer pool before it changes the interest rate. A wider pool of buyers means a lower yield demanded, and a lower yield means cheaper debt.
In day to day use, the rating is translated into a credit spread, which is the extra yield investors want above a government benchmark of similar maturity. A borrower in the A1 notch typically prices tighter than one in the A3 notch and wider than one rated Aa.
Treasurers watch that spread closely because it feeds directly into the cost of capital used in investment decisions. Ratings at this level are also written into contracts.
Loan agreements often contain a pricing grid, where the margin charged steps up if the rating falls and steps down if it improves, and some supply contracts and insurance arrangements require a counterparty to stay at or above a stated notch. That turns a rating change into an immediate cash consequence rather than a reputational one.
Two pieces of nuance matter. The agencies attach an outlook or a watch status, so a stable A1 and an A1 on negative watch are treated very differently by the market, and where agencies disagree the result is a split rating that is usually priced off the lower of the two.
Ratings are opinions rather than guarantees, and they are reviewed on the agency's own timetable, not the borrower's.
In practice
Real-world examples.
Example
A national utility holding an A1 rating refinances $300,000,000 of maturing debt. Because pension funds with rating-constrained mandates can buy the issue, the book is oversubscribed and the bond prices at the tight end of guidance. The treasurer reports an annual saving against the budgeted coupon.
Example
A listed engineering group is quoted a revolving credit margin of 1.05% while rated A1, with the pricing grid adding 0.30% if it slips to A3. When a large acquisition is proposed, the finance committee models the margin step-up as a real cost of the deal rather than a footnote.
Example
A city transport authority is told by its adviser that moving from A2 to A1 would cut its expected spread on a $120,000,000 issue by around 0.15%. It reduces short-term borrowing and builds reserves for two years to support the upgrade case, because the saving on one issue alone is worth $180,000 a year.
Formula
Calculation
All-in borrowing cost = benchmark yield + credit spread for the rating.
Annual interest cost = principal x all-in borrowing cost.
Suppose a manufacturer rated in the A1 notch issues a $50,000,000 five-year bond. The five-year government benchmark yield is 4.00% and investors demand a credit spread of 0.90% for this rating and maturity.
All-in borrowing cost = 4.00% + 0.90% = 4.90%.
Annual interest cost = $50,000,000 x 0.0490 = $2,450,000.
Total interest over five years = $2,450,000 x 5 = $12,250,000.
If the same issuer had been two notches lower and paid a 1.40% spread, the cost would be 5.40%, or $2,700,000 a year, so the two notches are worth $250,000 of annual interest.Case study
Seen in the real world.
The following is an illustrative, fictional example. Calderwell Industrial, an invented maker of industrial pumps, carried an A1 rating for a decade and borrowed comfortably on the strength of it.
When Calderwell announced a debt-funded acquisition, the agency placed the rating on negative outlook within a week. Nothing had changed in the company's trading, but the proposed leverage was higher than the band comfortably supported, and the market immediately widened the spread on its existing bonds. The finance director responded by funding part of the purchase with equity and committing to sell a non-core division, which restored the stable outlook before the next refinancing.
The illustrative point is that the rating moved on the plan, not on the results. Calderwell's board now tests every major financing decision against the rating band it wants to keep, and treats the agency's leverage threshold as a planning constraint.
Watch out
Common mistakes.
- Reading A1 as the best possible rating because it contains the number one, when it is the top notch of the A band and still four notches below the highest grade.
- Assuming an A1 borrower cannot default, when the rating expresses a low probability of default rather than none at all.
- Quoting a single rating when two agencies disagree, instead of disclosing the split and pricing off the lower notch.
Questions
People also ask.
How far is A1 from losing investment grade status?
Six notches, since the lowest investment grade rung is Baa3 and the first speculative grade rung below it is Ba1.
Does an upgrade to A1 reduce borrowing costs immediately?
Existing fixed coupons do not change, but new issues and any facility priced off a rating grid reprice, so the benefit arrives with the next transaction.
Who pays the agency for the rating?
In most cases the issuer pays for its own rating, which is why investors are expected to read the underlying analysis rather than rely on the letter alone.
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