Nearly half the amount solicitors pay out on negligence claims arises from their commercial work, new claims figures show.
The type of business generates a relatively small number of high value claims.
Commercial work generates just 12% of total claims.
In contrast, conveyancing accounts for 26% of the amount solicitors have to pay out but 38% of the total number of claims made against them.
Conveyancing includes drawing up deeds and titles to transfer ownership.
The figures are from the St Paul International Insurance, market leader in solicitors' professional indemnity insurance. It has about 25% of the market.
Claims manager Ian Bryant of St Paul said: "The majority of these claims arise from mistakes made in drafting, approving or advising on contract terms."
The data is included in St Paul's magazine for solicitors, On Risk.
