Turbo tax auto-inputs the first four letters of the entity. The IRS uses the first four letters of the last name (or first two or three if shorter last name).
I found this site helpful because it explains how the Special Name Control is established:
https://www.irs.gov/businesses/small-businesses-self-employed/how-your-name-control-is-assigned
I had to call The IRS Business Specialty line for this answer and I didn't believe it but it worked. TTax would not allow me to file form 1041. The IRS guy said to put in the first 4 letters of the Trust or Estate. This is the official name you put in when you applied for the EIN# for your Estate or Trust. It WORKED!! and TurboTax finished filing my return electronically. Leave it to IRS to through in a secret code that you would never guess.
My estate return is all ready to send electronically, but there is an error in the worksheet. ESTA is on it. What does that mean and what control should I enter. I am in Virginia
It would be best to give us a call here, so we can look at the return. @myersjb111