You can purchase a Japan Rail (JR) Pass up to 90 days (3 months) before you intend to exchange it in Japan. When you buy the pass from an authorized vendor, you receive an "Exchange Order." This physical or digital voucher must be turned in for the actual rail pass within three months of its issuance date. If you buy it too early (e.g., four months before your trip), the voucher will expire before you arrive. Once you are in Japan and have exchanged the voucher, you can choose a starting date for the pass that is within 30 days of the exchange. In 2026, many travelers use the official JR website to buy the pass, which allows for digital seat reservations up to one month in advance, even before arriving in the country.