I use the biggerpockets credit check.

I have a few business card but my favorite is PSECU personal credit card .

I set the Credit Score as 650+ negotiable in Zillow and I had two immediate applications with very bad scores. 

One influencer bragged, “When that apartment package got you approved for your luxury apartment in two weeks even though you had two evictions and a 500 credit score.”Greystar, the nation’s largest apartment landlord, says up to half of its applications in some Atlanta buildings are fraudulent.

But generally speaking, managing your credit score is a common task for real estate investors - especially for those who make use of credit in the purchase and rehab of properties.

Look at the items on the credit score. 

Pay the line of credit and then you'll have more leftover to buy more. 

Same holds true with business credit cards (usually after 90 days for credit cards).

Fill out an application or complete credit/background check, no. 

Set your goal on using your personal credit and cash.