Can I aggregate crypto transactions in the universal CSV file

[bmucklow]

I am a heavy crypto trader and I have over 15,000 transactions from this past year. The API connection to the exchange fails with a generic error but I suspect its because its over the transaction limit and times out. I can download the Gain and Loss report (Taxable Transactions, not 1099B)  from the exchange but it's over the 4,000 transaction limit of the CSV.  

I found TurboTax offers a Template CSV here:

https://ttlc.intuit.com/turbotax-support/en-us/help-article/cryptocurrency/create-csv-file-unsupport...

Can I aggregate my transactions in this CSV? Other competing tax tools have support documents on this subject and it appears that you can aggregate the transaction input. However I am wondering what are the rules for aggregating transactions that meet the CSV formatting requirements of TurboTax.

If I cannot aggregate into a single CSV am I allowed to break up the input into multiple 4000 transaction CSV files?

[CatinaT1]

You have a couple options:
 

1. You can break up your Gain/Loss form into multiple documents (about 1500 per CSV as to not overload the system and ensure a successful upload). Then upload each document one at a time for the provider.
2. Create a custom CSV (using the link you posted and following those steps to create the universal format CSV). If you create the custom CSV of the transactions, don't aggregate the transactions. Ideally, you need each transaction one at a time to properly identify the cost basis. Aggregating them may lead to errors in the gain/loss calculation due to not having the actual cost basis.