Credit ratings are linked to the individual not the property so unless you have a financial association with him (for example, joint bills or joint accounts) your credit rating will not be affected by him living in your property. Your ex-partner will not be able to charge rent to your new partner if he moves in as his name is not on the mortgage. However, if your new partner lives with you for some time and contributes financially to the household he may build up a beneficial interest in your property. This essentially means that although his name is not on the deeds he may be entitled to a percentage of the equity due to contributing financially to the household over an extended period of time.

This question has been answered by Christians Against Poverty, a leading debt charity offering hope and a solution to anyone in debt.