Help! BSed my salary by £20K more when headhunter asked

Headhunter contacted me a few weeks ago to see if I was interested in a new role. After expressing my interest, we scheduled an initial call screen. During the call he asked me what I'm currently earning. Now I'm never good with this question since if the figure you give is too high they'll move on, too low and they exploit you.

I figured I had nothing to lose so I quoted a figure £20K more than what I'm making, which as it happens is the exact salary the role pays lol. While I'm still a strong candidate, anything can happen and I might not get the offer.

But if I do, how screwed am I? Will they find out that my salary was nowhere near what I said it was? And if so what do I do? I'm in financial services but never had to deal with this before and I really want to land this role

TL;DR - BSed my current salary with a headhunter and might actually land the role. Not sure how to proceed if caught out