I can not help you clean your credit
If you lie to me
If you can not document what you say
When we challenge an item on your report it becomes a "he said she said thing"

Now if you are not in a hurry and the item is old say like 5 years.... If you do it in writing you have a chance. By challenging something that is older and in writing you are betting on the collection people being so overwhelm and it being so old that they will not respond in time and the item will disappear. I would put that chance at 50%. Maybe --- maybe not.
I had the opportunity to have a few beers with a collection manager the other night and he admits that once you pay off they don't care about reporting the item. Heck they got the money and you are a bum for not paying
BUT
If you paid the collection and you really did and we pull your credit 
We can request an update through the company we pulled the report from
It is generally a phone call and a simple yes or no
and like magic it is gone
But
Sometimes we need proof, so if you are paying off collections please keep copies of everything. Especially if the collection has been sold many times and you have say one bad cell phone bill, but it is with 4 different collection agencies. The one that you paid will give you a receipt and it will show say "Verizon Collection". We can then dispute the other 3 collections that say "Verizon Collection".
I have seen too many times
"I PAID THAT"
OR
"I HAVE NO IDEA WHAT THAT IS"
Then it comes back and guess what
The collection company claims it is you
So now what
We request them to send a copy of your signed contract and what the debt is for. Sometimes at this point you might remember it is really yours
BUT
I have seen these contracts come back and it is someone else that signed that contract or a complete forgery. If that is the case then we can get the item removed.
But we do need you to help us by being straight with us.
EDIT EDIT EDIT EDIT (ADDING MY COMMENT THAT WAS INSPIRED MY THE FIRST 3)
Funny but I forgot to put this in my orginal post and it would be unfair to edit and change it (but I will).... But as I am counseling borrowers with tough credit---- I relate my own stroy... yes a bad divorce and a closing of a business--- I have been there done that got the freaking t shirt. Close the door and tell me the truth--- I cant help you otherwise.
Remember the saying buyers are liers. I don't really belive that. It should read. Buyers are scared and they lie to protec themselves. The best way to avoid problems is to make them comfortable and let them know you are on their side.
Justin Thayer
Team Thayer Keller Williams
www.teamthayer.com
541-543-7287