I'm in the process of paying off all my credit cards before being pre-approved for a loan. Is there a length of time I should wait for my my FICO score to increase before getting a pre-approval? In other words, how long would it take for my FICO score to increase after I pay off my credit cards. I've heard 6 Months, 2-3 Months, and 1 week.I'm in the process of paying off all my credit cards before being pre-approved for a loan. Is there a length of time I should wait for my my FICO score to increase before getting a pre-approval? In other words, how long would it take for my FICO score to increase after I pay off my credit cards. I've heard 6 Months, 2-3 Months, and 1 week.