PaymentInput a payment takes (the account, the variants or an inline plan, the promo code) plus where the buyer is: address, shipping_address, tax_ids and ip_address. Tax is calculated for the shipping address, else the billing address, else the IP address, and located_by says which one priced it. A seller who collects no tax on the purchase needs no location at all.
Pass the quote’s id as quote_id when you create the payment and the buyer is charged exactly this quote: its purchase (which the payment may then omit), its promo code and its tax_amount, with no figure recomputed at charge time. A quote is priced once, may be consumed by one payment, and expires at expires_at; quote again whenever the cart, the promo code or the address changes. It is priced in the variants’ own currency unless you send presentment_currency (auto for the currency of the country Whop places the buyer’s ip_address in, or a currency code): every amount is then converted at an exchange_rate fixed until expires_at, the payment is charged in that currency at that rate, and recommended_currencies lists the currencies to offer the buyer. A quote located by ip_address is a preview: show it, then quote again with the buyer’s address to pay. tax_status says whether every line was priced (calculated), whether the seller collects no tax on this purchase (not_applicable), or whether tax could not be priced (unavailable, which a payment refuses: quote again, or charge without quote_id to have tax calculated at charge time).