Buy to Let

[oldexpat]

I have paid for my house in full and I am still in full time employment. Would it be possible for me to buy a place on mortgage with my current house as a back up and at the same time get another mortgage based on my earnings? This way I would have 3 houses, renting 2 out and having a mortgage on 2 of them which will be buy to let hopefully?

[buildersmate]

You are confusing two things.
1) The mortgage company wants some security (aka 'the house') to claw back if you seriously default on your payments.
2) The mortgage company wants to be reasonably sure that you have the wherewithall to pay the loan back, so that 1) is never invoked.
You will require to show BOTH of these for a mortgage to be granted.
In theory, you can borrow against the security of your existing property for another purpose (to finance a buy-to-let rental) - but the mortgage company reserves the decision whether to grant it to you and on what terms (interest rates).
You may be able to borrow enough on your existing house to finance 2 buy-to-lets - depends on how much and what the repayments would be.
The only way to answer this is to start touting the High Street for your business.