Maybe but at the moment I can afford it as I am working. when I retire I will have a drop in income and then the rent would be hard. Also the Mtg stays the same (ingoring interest rate changes) whereas rents go up

In an ideal world one would put the difference between the rent and the mtg payments in a savings account / pension but most people live to their salary

I have been watching some rents and while house prices have trebled over a ten year period rents have only gone up 40%. So mortgages will be higher and so will the interest payable. Add in the fact that many people have had a huge windfall in terms of unrealistically low interest rates reducing their mortgages substantially. So many buy to let landlords might have also benefited. Interest rates can now onluy go up and long term rates will be at least 5% and how many of you with mortgages will cope with your high mortgages at 6% and above?

I'll increase the rent, something which I've been good at not doing over the last 6 years.

In my area (I bought in 2008) the rent on similar houses to mine are roughly equal to my Mtg - just looked on right move. I was lucky enough to be able to put a 20% deposit down and have a 20 yr mtg. When we bought interest rates were at 5% so my Mtg would climb a bit above the rental rates but only to what we started with and we ahve used the falling rates to overpay the Mtg. However I asume if rates go up so buy to let landlords will put up rents to cover and of course rents go up with inflation

Our rent has only increased twice in the last six years and that was because we moved (three times to better properties).
Landlords cant on a whim raise rent, due to contracts and if they try to raise it too high then the tenant can move out.

And an empty property still costs money. So they can lose money waiting for a new tenant and if they ask too much then they remain empty for months.