Question about remitting sales tax to California

I will be operating my upcoming drop shipping home business out of the state of Pennsylvania. One of the suppliers I checked out on your listing has stated that any sales made to any purchasers in California requires that I collect a state tax from them and remit to California. I was under the impression that I would only be responsible for collecting sales tax from sales that came from customers in my home state. I would like your advice regarding am I supposed to collect sales tax from any orders that come from CA.

Couple of resources here that should assist you and others with the same question.

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