Affordability for most mortgages is usually assessed by calculating your income against your outgoings. However, buy to let mortgage operate quite differently. With a buy to let mortgage, affordability is assessed by calculating whether your rental income will cover the costs of the buy to let mortgage.
Nonetheless, there are lenders out there that require applicants to have a minimum income of £25,000 per annum whilst others do not require applicants to have an income.
Lenders typically require your rental income to cover your mortgage by 125-145%. Even so, it’s important to note that all lenders operate differently and have different criteria for assessing how much they can lend for a buy to let mortgage.