You might need the following documents for tax reporting and here is how to find them: 

Gain/loss statements

1. Go to settings > statement and taxes 

What is a Gain/Loss Statement?

Forms 1099-MISC

1. Go to settings > statement and taxes

What is a Form 1099-MISC?

Transaction history for the period

1. Mobile: Go to Settings > Statements & history > Transaction history > Select a year > download Exchange Transaction History 
2. Web: Go to Settings > Statements & history > Transaction history > Press download for Exchange Transaction History > set the date range

Other income earned on the exchange (via earn and staking):

1. Mobile: Go to Settings > Statements & history > Select a year > download Staking Transaction History
2. Web: Go to Settings > Statements & history > Press download for Staking Transaction History > set the date range