sole trader vs trade name

sole trader

noun
  • A type of enterprise or proprietorship which is owned by one person who is fully liable for the company's debts and fulfilment of contracts with his/her personal wealth unless incorporated. 

trade name

noun
  • The name under which a business or firm operates. 

  • A name used to identify a commercial product or service; may or may not be registered as a trademark. 

How often have the words sole trader and trade name occurred in a corpus of books? (source: Google Ngram Viewer )