"If you are at or above 640, you should be good. Otherwise, I'd recommend waiting if you can help it."
This is incorrect advice unless you are in an FHA loan currently or planning to purchase with an FHA loan. An FHA loan won't penalize you for the 640 whereas a conventional loan will. To get the same rate for a conventional loan that a person with a 740 credit score will get, you would have to pay 2.5 points up front. Look at it this way, if you have a $300,000 loan, you have to pay an additional $7,500 in closing costs just to get the going rate that a person with a 740 credit score would get for no points.
If you are looking to purchase with an FHA loan or you are refinancing an FHA loan, then you may be ok. If you are trying to refinance a conventional loan or plan on purchasing with a conventional loan, it will cost you dearly because of your score.
Tripoint Mortgage Group, inc