Hello Community, I completed form 8949 for a client. I took the information out of 1099-B and into 8949 and there were total of 17 transactions. Whenever I was ready to email the return to the client I noticed form 8453. Looks like this was triggered by form 8949 but why would I need 8453 to be mailed if I completed each of the transactions on 8949? If 8453 needs to be mailed, do I just attach 8949 with it?

Thanks Community. Much appreciated.