Professional indemnity insurance

Yes

Professional indemnity insurance is fully deductible as a business expense. Like public liability, it is a wholly business cost with no personal benefit element. It covers claims that your professional judgment, a design decision, a specification, a certificate you signed, caused someone a loss, which is a different risk from the injury and damage that public liability covers.

Common questions

Can I claim professional indemnity insurance?

Yes, in full. It is a business expense with no private use element.

I'm an electrician or gas engineer certifying my own work. Is PI relevant to me, and claimable?

Yes on both. If your work involves design choices, specifications or certification, PI covers claims that your professional judgment caused a loss, and the premium is fully deductible.

My certification body or a contract requires me to hold PI. Does that change anything?

No. Whether you hold it by choice or because a trade body, certification scheme or contract demands it, the premium is a business expense on the same basis.

Watch out for

Run-off cover, PI you keep paying after closing the business to cover past work, is not a normal trading expense because the trade has ended. Relief may still be available under the post-cessation rules; take advice before relying on it.
A combined trade policy (PI plus public liability plus tools) is claimable as a whole when every element covers the business.

Common mistakes

Assuming PI is only for offices and consultants. Design-and-build, certification and survey work in the trades all carry professional risk, and the premium is just as claimable.
Claiming run-off cover as a normal expense after the business has closed. Different rules apply; take advice.

Cash basis vs traditional accounting

Premiums are a day-to-day running cost on both methods: deduct what you paid in the year on cash basis, or apportion an annual premium across your year end on traditional accounting.