What is the Proof of Income for a Mortgage Loan?

A letter from your employer - Your lender will tell you what else is valid in their eyes

@Kimjousha321 I got a car loan recently in Portugal and I had to show my Australian pension payment for the last three months via my bank statements and I also included the dates of future payments of my pension for 2023.

Initially the bank [Primus] was reluctant to lend to a foreigner.  I had only been in Portugal since September 2022 but I did have my residency [CRUE].  However, in the end, after 4 days of deliberation, they decided I was a 'good' foreigner who would meet repayment obligations and not default.

I think being able to show future dates of payment of my pension every 4 weeks helped greatly as the bank could see where their regular and definite repayments would be coming from.

I would say therefore that bank statements showing regular deposits of income and confirmation of regular future income would be a good start for you.

When the bank required proof of income I jut showed them last year's income tax. The bank accepted it without question. In fact I used the same income receipt when I applied for my Residency Permit.

You must provide them with your tax return (declaração de IRS)  for at least the previous year. You can provide them with your monthly income receipts, as long as they have evidence of being periodic and not punctual. There is one important aspect that is the effort rate to pay the mortgage loan. This rate should not be more than 40% of your monthly income. Otherwise, it is very likely that they will refuse the amount requested for this loan.