There's no perfect way to avoid issues, but working with reputable vendors and paying material suppliers directly will be the best approach you can take. 

During COVID some of these HML put a pause on these loans and are now gradually re-offering them at less interesting terms.Aside from financing a successful flip comes down to having a good team (from contractors/sub contractors to material suppliers) and coordination/construction knowledge.

A lot of people may consider these options borderline reckless, but I've used the following sources at different points in time:Credit Cards - You can cash advance or pay suppliers directly.Personal Loans - I've used the following: Prosper, Lending Club, SoFi, Best Egg, Discover Personal Loans, USAA Personal Loans (these are by far the simplest, if you're a member).

This option might be preferable if you prefer a more hands-off approach to the renovation process.Contractor Relationships and Expertise --> Some contractors often have established relationships with suppliers, which can lead to volume discounts or preferential treatment. 

I have 20 years of hands on and administrative construction experience including market analysis, cost estimating, risk analysis, budgeting, purchasing, and relationship building with contractors and suppliers.   

Just bought my first investment property and looking for advice on best suppliers for rehab materials.

Anybody have any direct experience, or inputs into quality suppliers?

I pay $450 a window but I have a deal with my supplier, I give them a lot of work, etc.

Use lines of credit for materials from suppliers, they have cheap money.

Tyson just did what Walmart has been doing and getting all suppliers (vendor world) to have an office here.