so year 2013/14 I was self-employed, then had a job as bank staff for about a month then got this job.

Doing my tax return realise I don't have a P45 or anything from middle job - as I had to give it to new job, they have it but no record of what I earned/tax paid. They never gave me wage slips as it was all online and I wasn't there long enough for it to get setup.

I only earned about £200 the whole time I was there so should I guess the tax? try and calculate the tax? maybe I wouldn't have paid any as I hadn't got earnings declared for that year? just remove it from my return and hope they don't notice?