I US citizen currently live in the UK, but will be moving back to the US in the near future. I own a home in the UK, with a sizeable mortgage and a LTV ratio of about 70%. I would like to sell my home in the UK and use the proceeds as a down payment on a slightly more expensive house in the US such that the LTV ratio on the new house is 80%. In the absence of the UK mortgage, the mortgage on such a property would put my front-end DTI at around 28 and my US credit is very strong. If I include my UK mortgage, I would not be able to borrow sufficiently to buy the house in the US. I have a large enough emergency fund, that I could afford the mortgage payments and upkeep on both properties for 6 months if the UK sale falls through.
My goal is to have as little time between completing the sale of my UK house and closing on my US house. Presumably, before getting the loan the US lender will need to source the funds used for the down payment and verify that I have paid off my UK mortgage. Is this correct and if so, how long does it typically take? Is it the only thing to worry about?