Diary or Similar Record
You must keep an accurate diary or similar record of your losses and winnings.
Your diary should contain at least the following information.
- The date and type of your specific wager or wagering activity.
- The name and address or location of the gambling establishment.
- The names of other persons present with you at the gambling establishment.
- The amount(s) you won or lost.
This information is found in Publication 529, Miscellaneous Deductions.