9x salary or 9x salary plus tax credits plus maintenance?
My lender did include tax credits and cms agreed maintenance (plus bank statements proving it had been paid for a number of years) but the mortgage was 4x full household income with a 50% deposit (80k mortgage, 80k equity/deposit).
In the current financial climate I think 9x either is very unlikely, having a £180k mortgage on a £500k house, with a salary of only £20k is an eye-watering figure. CMS is reliant on the ex paying, and therefore having a job, is that guaranteed?
Has she done any sums yet?
180k over 25 years at 2% is approx £763 per month. That leaves (from the 20k salary) £900 per month for EVERYTHING ELSE. Council tax on a 500k house won't be cheap, nor will heating/electric bills. Add on the other household bills - water, phones, insurances, food, car maintenance, tax, fuel, insurance, kids expenses possibly, and there will be nothing left. One month of zero maintenance, for example, will plunge her into a debt she will struggle to escape.
What are your friend's circumstances? Does she need such an expensive place? What are the total marital assets? Will she have residency of the dc? How are the marital assets to be divided? Is there the potential for her to ask for a bigger share of the assets to home the children?