Surprisingly there’s actually not that much about you that is revealed to lenders when they conduct a credit search on you.
Aside from the obvious things like name, date of birth, and electoral roll information the following are typical of what’s shared with a lender;
Any current overdrafts you may have.
Public information records held against your name, like - CCJs (county court judgements), or even bankruptcies going back 6 years.
Information about your financial behaviour - e.g if you’ve made any missed payments or late payments and how many times this has happened.
Details of any hard credit searches carried out.
Financial associations and links to other people.
Fraud notifications - if you’ve been a victim through a CIFAS notification.
Current credit accounts are also listed.
For more info on what lenders can see, set up and check out your credit profile.