That depends on the product being taxed. I learned this in econ101 that the price elasticity of demand determines who bears the bulk of a tax. I don’t have references in my old textbooks handy, but here is exactly the same concept as I learned it[1]

Basically, if demand for a product is inelastic (eg. cigarettes, insulin) that will pretty much be 100% passed on to customers by the business. You can see the supplied link for examples where the seller has no choice but to eat the tax (or most of it) or people will just stop purchasing.

[1] https://www.khanacademy.org/economics-finance-domain/microec...