CRITICAL DIAGNOSTIC RE: TAXPAYER NAME WILL BE TRUNCATED. I THEN REMOVED FIRST PART OF HYPHENED LAST NAME OF SPOUSE. FILE LAUNCHED BUT WAS REJECTED. WHAT TO DO NOW?

Name control for individuals is usually the first four letters of the last name.  If an individual has a hyphenated last name, the name control is the first four characters from the first of the two last names.  Removing the first part of the spouse's hyphenated last name caused the rejection.  So don't do that.

IRS specifies a priority in abbreviating different parts of the names to meet the 35 character limitation: (1) Delete the spouse's middle initial; (2) Delete the taxpayer's middle initial; (3) Use initials only for the spouse's first name; (4) Use initials only for the taxpayer's first name; (5) Abbreviate the spouse's last name by removing the vowels beginning with vowels at the end of the last name; (6) If further reduction is still needed, abbreviate the taxpayer's last name by removing the vowels beginning with vowels at the end of the last name.

BUT never remove the first four characters of the last name of the taxpayer or spouse!

You can also choose to do nothing and let the truncation happen.  Perhaps it will slow processing the return and delay a refund.  But this way, printed copies of the return will have the taxpayers' names in full.

I just disable the efile error checker and send the efile.  Returns get accepted and haven't had an issue.