File 12 · Carrier · Boston, MA
Liberty Mutual Surety
Global contract surety — company calls itself the world’s largest surety
Liberty Mutual’s commercial surety page describes the group as the world’s largest surety and publishes financial-strength ratings of A (Excellent) from AM Best, A2 from Moody’s, and A from S&P. Distribution is through brokers and agents on mid-to-large contract accounts as well as commercial lines.
“World’s largest surety” is Liberty’s claim, sourced to their commercial surety page. We repeat it as a labeled company statement, not as our measurement.
Best for contractors who already have a broker relationship. Not a click-to-bind license-bond shop.
Bond series on this file
What they claim to write
Series A
License & Permit
Most regulated businesses post a license or permit bond before a state will issue or renew the license. The bond guarantees compliance with the statute — it is not insurance for the principal.
Series B
Contract / Performance
Construction and public-works contracts ask the contractor to guarantee the bid, the work, and the subcontractors. These are underwritten on financials and experience, not just a credit score.
Series C
Commercial
Commercial surety covers the bonds that sit beside a license or a jobsite: employee dishonesty, public official, lost-instrument, and a long tail of miscellaneous forms.
Typical desks: Large contractors · Brokers · Infrastructure