Based on the additional information provided here:

https://accountants-community.intuit.com/questions/1839967-my-client-is-a-va-resident-with-a-busines...

I agree that your client cannot use the border state rule since the K-1 income is on Schedule E and not Schedule C.  See this ruling (but sounds like I'm preaching to the choir):

https://tax.virginia.gov/laws-rules-decisions/rulings-tax-commissioner/15-214

"Further, only earned income (wages and salaries) or business income reported on federal form Schedule C is eligible for the special rule.  See P.D. 04-125 (9/16/2004). Because it was reported on federal form Schedule E, the partnership income generated in North Carolina is not eligible for the special border state rule."

I'm assuming you have K-1 income and not a loss that may be suspended for some reason.

I don't know Lacerte though so I don't know how you would indicate not eligible.  Let me shout out to someone else who does use Lacerte and is in one of our border states.

Rick