There's no X that defines "too many" for everyone out there. If you can't reasonably manage X then X is too many. From a FICO scoring standpoint it's generally best to have at least 2 or 3 credit cards reporting. One can certainly have many more. I don't have as many as thom02099 but I have 10 total, have a use for all of them and have no problems with managing them.
If you're worried about your score then consider the usual suspects:http://www.myfico.com/crediteducation/whatsinyourscore.aspx
As others have indicated, number of cards really doesn't mean much. A lot of hits due to new inquiries and hits to AAoA from new accounts can adversely impact your score. However, to what extent varies depending one one's credit. Generally speaking, a thicker credit profile won't be hurt quite as much as a thinner one.
abeer wrote:I used it last month and paid all the balance today and I want to close it, but scared.. what if it lowers my score?
The major hit from closure is due to the reduction in utilization. While we can't tell you that you'll lose X points you can calculate your utilization before and after to help you with you decision making.
abeer wrote:Do you think it's a good idea??
Your call to make. Good is highly subjective. I didn't see any point in keeping my Capital One rebuilder cards that didn't grow with me but YMMV. Some prefer to see if CO will give them CL's and APR reductions to keep the account age. Just keep in mind that even if you close it the account will still factor in to your AAoA until the closed account falls off your reports around 10 years down the road.
abeer wrote:or will it have a bad impact on my score?
To even guess we'd need a lot more info regarding your credit. What's you individual and overall utilization? AAoA? Are these 5 cards the only credit accounts you have? Are all your inquiries with the same CRA? What's the inquiry count for each CRA and age of the inquiries?
Also keep in mind that since there are 3 CRA's you have a score based on information in your report with each of those CRA's. What the auto loan creditor will see all depends on what they pull. When was the last time you pulled and reviewed all your reports? Do you have any scores?