questions regarding manually editing/creating 1099-B entries for a same stock sold across multiple broker accounts.

[tpe]

1. I plan to import the 1099-B from two brokerage accounts when they are available.
2. The problem is that the wash sales are across different brokerage accounts, and the broker where I sold doesn't know about a purchase from a different broker.
3. I am preparing my knowledge now because I never deal this before.
4. Let me give you one example:
4.1 I bought 200 shares of ABC for 10 dollars in 2018 in broker A.
4.2 I bought 100 shares of ABC for 5 dollars on 3/21/2019 in broker B.
4.3 I sold 100 shares of ABC for 4 dollars on 4/11/2019 in broker B.
4.4 I sold 100 shares of ABC for 3 dollars on 5/2/2019 in broker A.
4.5 I sold 100 shares of ABC for 2 dollars on 12/18/2019 in broker A to close out this looser for good.

So, broker A does not know I have shares in broker B and vice versa. I guess 1099-B from broker A and B will not calculate wash sale.

Obviously 4.3 is a wash sale. I think I need to  modify this sale record to put in wash sale amount $600, new acquired date from 4.1 and new acquired amount for 100 shares from 4.1. By doing this what category I need to put this sale record in? short term cost base reported, short term cost base not reported or short term sale not reported?  Do I need to put in the code T besides W?

Then I need to modify the sale reported by broker A for 4.5 with new acquired date from 4.2, new acquired amount from 4.2 and add wash amount $600 from 4.3 to calculate new cost base. For this entry 4.5 I probably need the code B but not sure the code T. By doing this what category I need to put this in? long term cost base reported, long term cost base not reported or long term not reported?

Please help!

[Critter]

When you are done entering all your sales transactions, you'll eventually come to the Here's the investment sales info we have so far screen. Here you can edit, delete, or enter more sales.

[fanfare]

Every transaction must be entered.

There is no reason to change any date sold or date acquired.

If a sale is a wash, add the denied loss to the basis of the buy transaction that caused a wash sale.

Your sales are category A, but you are modifying the cost basis for a certain number of transactions since the brokers involved do not have complete information.

[fanfare · Accepted solution]

Every transaction with adjustments must be entered on Form 8949. In your situation, both the wash sale and the triggering buy are in this category since you are adjusting that basis.

But if you did not close the triggering buy, it would not be reported.

Your other transactions  with no adjustments can also be entered on 8949 if you chose to do so, but do not have to be. This depends on how many transactions you executed, and whether your brokers support TurboTax Import.