Surety Bond Calculator

Credit score is the underwriter's primary proxy for default risk on a surety bond, since the bond guarantees the obligee (the party requiring the bond) will be made whole if the principal fails to perform — a lower credit score signals a higher chance of that happening, which the base rate tiers in this calculator reflect directly. It typically has a bigger effect on premium than any single other factor, including years in business or bond type.

Credit score maps to a discrete rate tier rather than a smooth sliding scale in real surety underwriting, and this calculator mirrors that: crossing a tier boundary (600, 650, or 700) changes the base rate applied to the entire bond amount, not just the marginal difference. That means a score of 699 versus 700 — one point apart — can land in noticeably different premium tiers, even though scores of 690 and 699 within the same tier produce identical rates.

Yes, in this calculator's model — 5+ years earns a discount factor, and 10+ years earns a larger one, reflecting the real-world underwriting logic that an established track record in the trade reduces perceived risk. Experience is a smaller lever than credit score, though: the discount factors here are modest (roughly 8-15% off) compared to the multiple-times difference between credit tiers.

Different bond types cover different obligations and carry different claim frequencies in practice — license/permit bonds tend to see fewer and smaller claims than contract/performance or court/judicial bonds, so this calculator applies a lower risk multiplier to license/permit bonds and a higher one to court/judicial bonds, holding everything else (credit score, amount, experience) fixed.