An average cost for professional indemnity insurance is a figure about the wrong population. It averages across professions whose premiums differ by multiples, across firms of every size, and across limits that were chosen for different reasons. It is accurate about the set it was drawn from and predicts nothing about a particular business.
What the published averages measure
The premiums actually paid through one channel over a period. That mixes a bookkeeper with a structural engineer, a sole trader with a twenty person practice, and a modest limit with a large one. Change the mix and the average moves without anything about insurance having changed.
Why the spread is so wide
Profession sets the band and the bands differ by multiples. Fee income moves within the band. The limit, the excess, the claims history and the market cycle each move it again. An average across all of that is a number true of almost nobody in the sample.
What is worth comparing
Your own renewal against two or three quotes on an identical specification: same activity description, same income figure, same limit, same excess. That comparison is real, takes half an hour, and answers the question the average was standing in for.
When an average is useful
As direction of travel across a profession rather than as a level. An average that has risen sharply is a reason to start renewal early and use a broker. It is not a target price for any particular firm, and treating it as one produces a frustrating conversation with every insurer.
Questions people ask about professional indemnity insurance average cost
Is there a reliable average?
Not one that predicts your premium. The bands by profession differ by multiples, so an average across them describes nobody.
What should I compare instead?
Your renewal against two or three quotes on an identical specification. Half an hour, once a year.
Is an average ever useful?
As direction of travel across a profession. A sharply rising average is a reason to start renewal early.