Merchant of record
The legal entity that formally sells to the customer, and therefore owns the tax, the refunds and the chargebacks.
It's the name on the card statement, which is not always the company that built the product. The merchant of record (MoR) is party to the sales contract, calculates and remits VAT or sales tax in every jurisdiction, handles refunds and eats the cost when a customer disputes a charge. With an ordinary processor like Stripe, that's you. With an MoR service like Paddle or FastSpring, the service effectively buys the product from you and resells it.
The model caught on with small software companies after the EU started taxing digital services in the buyer's country in 2015, turning every one-person shop into a tax filer in 27 member states. The trade-off is a fatter fee per transaction. By this definition, the App Store and Google Play are the largest merchants of record on the planet.