We have some existing customers that have small line amounts on their line of credit accounts attached to their checking account. We would like to pull credit bureaus on these customers and decide from that whether or not to raise their credit limit. Is that permissible since these are open end and we would be reviewing and possibly modifying the existing account? Or is this somehow prescreening?

This is permissible - read the Gowan letter:

http://www.ftc.gov/os/statutes/fcra/gowen.shtm

"Like creditors, banks and others may need to consult a consumer's report in order to determine whether the consumer's current account terms should be modified. For example, the institution may provide more favorable pricing terms after consulting the report. The permissible purpose created by this provision, however, is limited to an account review for the purpose of deciding whether to retain or modify current account terms."

Thank you!