How much professional indemnity insurance you need in the UK is decided by the regulator where one applies, the contract where one exists, and your own judgement about what a client could lose. Those three, in that order, answer it completely.
Where a UK regulator sets a floor
Solicitors have minimum terms and a minimum limit set by the regulator. Accountants in practice have limits linked to fee income under institute rules. Architects, financial advisers and several healthcare professions each have their own requirements. Check the current rules rather than last year's figure.
What UK contracts typically require
Corporate engagements state a figure in the terms. Public sector frameworks state it in the specification, sometimes with insurer criteria and a post completion maintenance period. Recruitment agencies state it before an engagement starts. All of them are minimums rather than assessments.
Your own judgement above those
Size the limit against what a client could lose if the work were wrong, then check whether defence costs sit inside or outside it and whether the limit is per claim or in the aggregate. Those two details decide what the figure is actually worth on a contested claim.
Questions people ask about how much professional indemnity insurance do i need uk
Is there a standard UK limit?
No. Regulated professions have floors set by their regulator and contracts state minimums. Neither is an assessment of your risk.
Should I buy above the contract figure?
Often. The contract figure is the minimum a client will accept, and the loss they could suffer is unrelated to it.
Per claim or aggregate?
Ask. An aggregate limit can be exhausted by one claim, leaving the rest of the year uncovered.