Hello,
I was wondering if a subsidiary company could be registered under a sole proprietor (Business name)?

Basically can I have a subsidiary DEF under Business name ABC, or can only groups have subsidiary?

In order to supply the varying needs of the community, and make the consumer enjoy their output of production, many form of Business units have developed rapidly. In Nigeria, and nearly all west Africa countries, the commonest form of business unit is the sole trader.

Sole Proprietorship Defined
A sole trader is the form of business in which the control, finance, organization and management is solely done by a single person, who invariably is the owner of the business. This means that in the sole
proprietorship, the individual owns the business, assumes all risk and operates the firm for his own personal interest. Additionally, this form of ownership is ideally suited for the small business, especially when it is just beginning ( since flexibility and personal attention are extremely important. The sole trader was the earliest form of business organization, and at present, he is still the most usual form, particularly in retail trade.

Apart from the ordinary retail trade, the sole trader can be found in such service trades as decorator, artist, painter, mechanics, plumber, electricians and other professional trades such as architect, surveyor, business consultant, accountant, doctor, and so on. It is interesting to note that a sole trader deals mainly on commodities that are regular in demand, e.g foodstuffs, provisions small- size contract.
https://businessplanhub.com.ng/the-sole-proprietorship/#more-188