What difference between 支付 and 付款 ？

支付 and 付款 both are Verb, meaning "to pay".

支付 is the process of exercising an obligation to pay what is often called an obligatory fee;
付款 is the act of the payer paying a certain amount to the holder in order to terminate the relationship between the bill;

支付 is mandatory, generally stipulated by national laws and regulations, is the performance of obligations or compulsory payment;
付款 is not mandatory and is a more personal initiative;

在台灣很少用支付這個詞。大部分都是用付款。妳要怎麼付款？因為用錢（現金）付款，還是比較多人這樣子做。支付比較現代用語。我是這麼分析的。

支付 y 付款: pagar 请问你的付款/支付方式是现金还是信用卡？

付款 is a separable word. u can add 了 n 一下 between 付 n 款, so u can say 付了款n 付一下款.支付 is not a separable word. so u cant say 支一下付. u can say 支付了. of course u can say 付款了 bc 付款 is a common verb.

支付 - Verb -example - 我没有带现金，只能用信用卡💳支付。
付钱- Verb - example - 付钱的时候我发现钱包👛不见了。

我每學期都需要支付我自己的學費和房租。（用在大的支出，比較書面語）
你要怎麼付款（錢）？付款的方式。（現金還是信用卡）
付款不能用在例句1，但是支付可以用在例句1和2