HMDA purpose is Refinance – paid off small loan on primary residence which was pledged as the collateral and paid off large mortgage in business name.
• HOEPA – does Reg Z apply for this loan?
• Rate Spread – does Reg Z apply for this loan?

The largest part of the loan was for the business.

Thanks...

It sounds like this loan would be exempt from Reg. Z as business purpose, therefore, HOEPA would not apply and the rate spread would be recorded as "NA".

Is there a standard when a loan is split between business and personal? Is it by whichever is largest?

The primary purpose of the loan dictates if it will be a business or consumer purpose loan. The problem is the regulations do not define "primary purpose". Most use the the 50/50 split. If more than 50% of the proceeds are for one purpose or the other that is how they classify the loan.