If you and another person (or group of people) went in a pool to buy a bunch of lottery tickets, and win, how does taxation work for people who split lottery winnings? Does one person claim the winnings and then "gift" the amounts to the others, or can the winnings be split before taxation and then each individual will just pay their own taxes?
When you win a lottery or have other gambling winnings (over the threshold), you will receive a W-2G form from the payer. You could submit IRS form 5754 to the payer to inform them to split the winnings and issue separate W-2G forms accordingly.
Note that certain payers do not honor the form and will only distribute a single W-2G form. (The World Series of Poker is an example.)