Self employed people fall into different categories. Some lenders will treat people who have 3 years accounts as status cases. The amount of proof of income will dictate how much risk the lender judges the borrower to be. For example, newly self employed people are starting out on an uncertain path, therefore lenders may be wary of lending high loans to value.
Self employed remortgages are sometimes used to fund business development and growth. Self employed people do of course remortgge for all the same reasons as employed people- to get a better rate; to release equity; to buy a car; to go on holiday; to pay for a wedding or other event; to consolidate debt.
Problems in the mortgage market mean that mortgage options have shrunk significantly. Nevertheless, remortgages are still available for self employed people with different credit and emplyment status.