Look for the serial number on the back of the CD/DVD case, on a sticker inside the case, or on the front page of the printed manual.

Review the email sent to you after your purchase; serial numbers (e.g., starting with "ATS9" for older versions like TS2009) are often included there.

Check the My Digital Downloads page in your MyTrainz account. Your serial number and download link will be listed under the appropriate item.

For , which is primarily a mobile version of the game, a dedicated serial number is typically not required . Modern versions of Trainz, including mobile and digital store editions, use your MyTrainz account login and password to verify ownership and authorize the game. How to Find or Register Your Serial Number