The IRS matches the first four characters for name control as Anna and Lisa explained.

If your client's entity name has special characters or spaces in the first four characters, there is a standard convention to adapt that; you don't have to worry about that convention as the software will manage that automatically but it does mean that you should:

1. ensure the entity name (more than the first four characters) is correct; and
2. do not convert symbols like the ampersand (i.e. &) into words such as "and" (as in changing "AB & CD" into "AB and CD") because that will cause a mismatch.

You can read more about name control for 1065 on this IRS webpage: https://www.irs.gov/e-file-providers/using-the-correct-name-control-in-e-filing-partnership-tax-retu...