Credit is king. There are hard and fast numbers that you simple must be above to get a loan. When you say being "worked on", does that mean by you or a professional? If it is just being worked on by you, you could do more short term damage than good if you are not careful. It is best to speak to someone that knows the ropes. I have only heard bits a pieces from people that repair credit and it is a complicated dance they do to boost scores. If you would like the contact info for a local mortgage broker that works specifically with people that need credit advice and help, let me know.