You will need certain documents when you apply for a mortgage, and you should keep a copy of anything you give to a lender or broker.
Proof of ID, proof of address and proof of your Personal Public Service Number (PPSN)
Proof of income: latest P60, payslips, certified accounts if self-employed
Evidence of how you manage your money such as current and loan account statements for the last three to 12 months, depending on the lender
Her is Permanent TSB’s full list of documents required here.
Her is AIB’s full list of documents required here.
You can see that the lists are very similar, which is the same with all other lenders.
These lists will not be complete for everybody as they do not take account of your individual circumstances.