When someone contests items on their credit report in writing, how long does it take the bureaus to respond?

I believe that the credit bureaus are allowed 30 working days to investigate a dispute from a consumer. This would translate to about 45 calendar days. If you need a disputed item corrected more quick, there are services available that claim to do this in as little as a week. If time is of the essence; as in increasing your FICO scores to qualify for a new mortgage, then that may be the route to go. Those companies charge $ per trade line, per credit bureau (Experian, Equifax & TransUnion).