Yes you need to register your business and pay sales tax on all taxable products. It is each vendor’s responsibility to know their own personal tax requirements, and we recommend working with your tax professional to ensure that you are in compliance.  Please direct any questions to:
PA DOR: More Info Here or contact 717-425-2495 Ext. 72100 or ra-pabustaxreg@pa.gov
NJ DOR: More Info Here and Here or contact 609-292-9292, x1
For Chestnut Hill vendors~Philly DOR: Info here or contact 215-686-6600 or revenuetaxadvisors@phila.gov
For Bryn Mawr vendors~Lower Merion Twp Finance: More Info here regarding the $20 annual license or contact 610-645-6142 or  businesslicense@lowermerion.org