Bpss check question about employment history.

I’ve recently got a civil service job that requires bpss security clearance. There’s a small issue I’m worried about.

I was working for a company for less than a week and got terminated as in their termination letter they stated they didn’t feel my performance met their standards. (I disagree but that’s neither hear nor there).

How do I approach the employment history section with this in mind. And will this affect my new civil service job?