Hi cece, I have been an indirect lender of 15 years and know all about credit. Your score WILL NOT drop 200 points from a small amount past due.....
Nor do debt to income ratios drop a score. Here is a list, of what WILL drop your score, (in my experience, and I have a LOT of experience in getting people 'bought', - that is the term in getting people loans, and argueing their credit scores)......
1.) If all of your balances are high, this is the NUMBER 1 thing that will drop your score. EVEN MORE THAN LATE PAYMENTS............ here is the reason why.... Statistically, when people pay late, but pay, and don't have very high balances, or closed accounts, they are just 'slow credit' people....... However, when people have good credit, and they have a lot of credit out there, it can reach a point where they have legit reasons to go bankrupt, and it fields the computers as high high risk.... (anotherwords, say you have a 200,000 mortgage, plus a car loan for you and your son, and say 5 credit cards.- then lets say, all your cards have a 5,000 max limit, and they are being paid on time, but balances are around 3500 each, or 4,000 each.) technically you could say, "hey I'm going to get as much as I can with my good credit, and walk away.) this is unfortunate, but the statistcs show this happens much more than people with 'slow' credit..... so it makes your score drop HUGE!!
2.) if you co-signed for ANYTHING--- if there are late payments, they WILL show on your credit
3.) If there are any chargeoffs, or leins, (that you may not even know about) --- say medical bills that your insurance didn't cover, and you didn't realize you owed, (can go as a charge off or lein)- I've seen alot of that---- impacts your credit HUGE!!
Those are the biggies.
The only time debt to income comes into play, is when you are actually applying for the loan itself. Say if on your credit app, you put that you make 50,000 per year, and your bills (as reflected in your credit report) show that your payments each month equal 4,000 per month, the computer will 'kick' the app and decline it due to obvious payment to income guidelines, but this has nothing to do with your score.
Hope this helps.
Take care, any more questions, please ask,
love,
cess