Professional indemnity insurance cost varies more by activity than by anything else, which is why no average is useful. A bookkeeper and a structural engineer of the same size are in completely different markets, and the five drivers below explain almost all of the difference between any two quotes.
The activity, which dominates
Insurers rate professional indemnity by what you do, because the claims records differ enormously. Low frequency, low severity activities price cheaply; design, financial advice, surveying and anything touching construction price higher. Declaring the activity precisely is what gets you the right band rather than a cautious one.
Fee income and the limit
Income is a proxy for how much work is exposed, and the limit is what you are buying. Doubling the limit rarely doubles the premium, because the insurer's expected loss is concentrated in smaller claims, which makes a higher limit better value than buyers expect.
Claims history and the contracts you sign
A claim, even one that settled for nothing, is underwritten. So are your contract terms: a consultancy with liability caps, a clear scope and a consequential loss exclusion presents a smaller exposure than one working on emails. Insurers ask, and the answer moves the price.
What to do with all that
Declare activities precisely, tidy the contracts, and buy the limit the client requires rather than the cheapest band. Shopping the same risk to three brokers moves the price less than describing the risk properly does, which is the opposite of what most buyers assume.
Questions people ask about professional indemnity insurance cost
Is there an average price?
None worth quoting. The activity alone moves the premium by multiples, so an average across professions describes nobody.
Does a higher limit cost much more?
Less than proportionally. The insurer's expected loss sits in the smaller claims, which makes a higher limit unusually good value.
Does a past claim matter?
Yes, even one that settled for nothing. It is underwritten, and what changed afterwards is what insurers want to know.
What is the cheapest way to lower it?
Describe the activity precisely and tidy your contract terms. Both do more than shopping the same risk around.