How do I know if my 8949 was filed electronically? I just e-filed my tax return for 2021

[TomK100]

If you're e-filing, you only need to mail the IRS a copy of your 8949, along with Form 8453, if you entered sales section totals for one or more sales categories (instead of each individual sale) AND one of the following is true:

• The sales category for one or more summaries is something other than box A (short-term covered) or box D (long-term covered), or
• The box A or box D summary includes adjustments (typically listed in boxes 1f or 1g on your broker statement)

If you're required to mail in forms 8949 and 8453, do so within 3 days after the IRS has accepted your e-file. Here's the mailing address:

Internal Revenue Service
Attn: Shipping and Receiving, 0254
Receipt and Control Branch
Austin, TX 73344-0254