p45 filling

Hiya, this feels really stupid but i quit my job like 5 months ago and have just started at a enw one who wnats my p45, i sent it to them assuming my employer is the one who fills it out, but realised after it was empty. google and all the websites say your employer should give you a p45, but no one has explicitly mentioned if they give it to you with all the details written already or if the employee is meant to fill it out after, at least none that ive found. Ive tried to complete it as like i have access to everything it asks for i think but im worried its wrong. am i meant to be filling it out in the first place?

Your previous employer (the one you left) provides you with a completed P45 which contains details including how much you earned during the tax year, and how much tax you paid.

You give Part 2 and 3 to your new employer, and retain Part 1A for your own records.

Your previous employer (the one you left) provides you with a completed P45 which contains details including how much you earned during the tax year, and how much tax you paid.

You give Part 2 and 3 to your new employer, and retain Part 1A for your own records.