How to Handle a Sale Mid-Year?

[justatester]

We have a plan that has 2 employers (A&B). On 4/1, Employer B spun-out and created a new plan. On 7/1, Employer B was sold and Employer A & B were no longer related.

For testing, we would like to test the Employer A plan from 1/1-12/31 including Employer B contributions from 1/1/-6/30 (Q1 made under plan A and Q2 made under plan B). Then test Employer B as a separate, unrelated plan from 7/1/-12/31. Is this reasonable?

If yes, how would you handle compensation for those very high paid HCEs. For example: Employer B employee earns $300,000 from 1/1-6/30 and contributes $10,000. Then from 7/1-12/31 earns another $300,000 and contributes $7,500. Can I apply the $255,000 comp limit separately for each plan and test the contributions as if contributed to two unrelated plans (A: 10,000/255,000 & B: 7,500/255,000)?

Do I need to worry about HCE mandatory aggregation post 7/1?

Any thoughts would be greatly appreciated!