Realize that you do not NEED their 1099 to file. Your records should reflect your earnings whether you are a cash or accrual filer. While it is nice to have in hand, rarely do the 1099s from MSCs match up to your reality whether you are cash or accrual. (If you are cash they may include checks they wrote on 12/31/2020 which you didn't receive until 1/12/2021 so would not be included in your 2020 income. If you are accrual they may still have owed you money from 2020 after 1/1/2021.)