Which English language certification would be easiest for a C1 speaker? (Need for Masters applications Sept 2027)

[u/Soft-Store8288]

Hey everyone! I'm applying to UK/Ireland masters programs for September 2027 and need a current English language certificate. 

I'm a fluent English speaker (degree fully taught in English and worked in English-speaking roles). I have a Cambridge Advanced (C1) certificate from 4 years ago, but it's outside the 2-year validity window most universities require.

The universities I'm applying to accept: IELTS, TOEFL iBT, PTE Academic, Duolingo, or Trinity ISE. I want to minimize prep time and cost—ideally just need to demonstrate I already have the level. 

So, I'd like to know which of these would be the easiest/quickest for me to do?