If they purchased the property as a rental and the first tenants were their children, with a lease and rental payments, it would be business purpose.
Review the commentary re rental real estate.http://www.bankersonline.com/regs/12-1026/12-1026-003.htmlHowever
, you should review this with legal counsel:
Official Interpretations of this section.
1. Foreign applicability. Regulation Z applies to all persons (including branches of foreign banks and sellers located in the United States) that extend consumer credit to residents (including resident aliens) of any state as defined in §1026.2. If an account is located in the United States and credit is extended to a U.S. resident, the transaction is subject to the regulation. This will be the case whether or not a particular advance or purchase on the account takes place in the United States and whether or not the extender of credit is chartered or based in the United States or a foreign country. For example, if a U.S. resident has a credit card account located in the consumer's state issued by a bank (whether U.S. or foreign-based), the account is covered by the regulation, including extensions of credit under the account that occur outside the United States. In contrast, if a U.S. resident residing or visiting abroad, or a foreign national abroad, opens a credit card account issued by a foreign branch of a U.S. bank, the account is not covered by the regulation.