The answer is, it’s not black or white. Anything in family law can be agreed to, meaning that things in family law happen either by agreement of the parties and counsel or by court order. If one person wants to use a company’s accountant, that’s fine so long as the other spouse agrees to that number.
If the case is going to go to litigation in front of a judicial officer, the person who is using the company accountant usually needs to hire a forensic accountant to do an outside analysis. That’s because people who work for the company usually are biased to the company or the owner of the company.
If you’re looking to value a business, you technically can use the inside accountant and not hire an outside professional. The person who owns the business or the person who operates the business can use the business accountant to generate a number, and if both spouses agree to that number, then that number can be used for purposes of settlement.
If the out spouse, meaning the spouse that doesn’t operate the business has any suspicions that that number is not correct, it’s not a good idea to use that number and it’s a good idea to hire an outside forensic accountant to get an accurate reading of the value of the business.