Translation's insurance question has sharpened in the machine-translation era: when you sign off post-edited MT output and an error slips through, is that covered? The specialist market says it can be – if the wording addresses it.
Buy PI that names the way you actually work – MTPE, certified documents, your specialist domains, your clients' jurisdictions – and mirror the limit in your contracts' liability caps, as CIOL advises. At under £200 a year for most freelancers, the premium is trivial; an uncovered error in a filed legal translation is not. Interpreters: your spoken-work risks differ – see our interpreter guide.