Is there a term or phrase for the one paying a bill that is later split?

Sometimes when splitting bills one of the group members has to pay the entire bill first to later be reimbursed by the other group members. Is there an English term for who that person is or what the person does?

Simple situation example:

I can [...] if you pay me back tomorrow.

Solution 1:

Although I can think of no words to specifically refer to the person who is reimbursed for paying the entirety of a split bill, some more general appellations for such a person include reimbursee or payer.

Additionally, those who must pay the reimbursee back could be called repayers.

Solution 2:

Also consider the terms
• banker (from en.wiktionary, it has senses “One who conducts the business of banking; one who, individually, or as a member of a company, keeps an establishment for the deposit or loan of money, or for traffic in money, bills of exchange, etc” and “The dealer, or one who keeps the bank in a gambling house”). In the game of Monopoly, the banker is any player designated to handle the supply of cash used to pay players as they pass Go, or win or lose money via Community Chest or Chance, etc.
• stakeholder, “A person holding the stakes of bettors, with the responsibility of delivering the pot to the winner of the bet” and “An escrow agent or custodian”, where a custodian is “A person entrusted with the custody or care of something or someone; a caretaker or keeper”
• nominee, “A person named, or designated, by another, to any office, duty, or position...” and “A person or organisation in whose name a security is registered though true ownership is held by another party...”

Some of the above terms are reversed in sense from what's suitable for the question, or certain details in their definitions conflict with the question, but they will serve ironically.