Before I go digging around, can anyone share their experience of buying a second home, while still having a mortgage on their first. Specifically where the first mortgage is very low LTV (<30%). What kind of impact does this have on the affordability calculation, does it vary with different banks ie do some of them simply deduct the full repayment of M1, do some of them exclude it from calcs on the basis that it is above water after tax, do some of them include a portion of the after tax cashflow as income? I know I can call around each bank or go to a broker but just wanted to see if anyone had recent experience. Fully aware of the potential pitfalls of being a landlord, change of M1 to a BTL rate etc. TIA.