This is one of the biggest points of confusion. Many people assume that once they pay off a collection agency, the negative mark will vanish from their credit report. Unfortunately, that's not how it works.
When you pay a collection, the agency typically updates the account status with the credit bureaus from 'unpaid collection' to 'paid collection' or 'paid in full.' While paying your debts is the right thing to do and can look better to some manual underwriters, a paid collection is still a negative entry. It indicates a past failure to pay a debt as agreed, and it can still lower your FICO Score.
Think about it from the bureau's perspective: their job is to report your credit history accurately. The fact that an account went to collections and was later paid is, technically, an accurate historical record.
What About 'Pay for Delete'?
'Pay for delete' is an informal negotiation strategy where you offer to pay the collection account (in full or a settled amount) in exchange for the collection agency agreeing to completely remove the account from your credit report.
Crucially, this agreement is with the collection agency, not the credit bureau.
If the agency agrees, they will send a request to the credit bureaus to delete the entire tradeline. The bureau is simply acting on the updated information from the furnisher. If you attempt this strategy, always get the agreement in writing before you send any payment. Not all collectors offer this, and the major credit bureaus officially discourage the practice, but it remains a common negotiation tactic.