As the term 'sole practitioner' (or 'sole trader') suggests, this is a type of architectural practice with only one individual. A sole practitioner may contract work out to others and employ staff, however he or she is the sole business partner.
This is the simplest and cheapest form of practice to set up. As a sole practitioner, the architect will be personally entitled to all profits but also exposed to all the risks and personally responsible for all debts and liabilities. The sole trader also pays tax at the personal income tax rate but can offset the expenses of earning income as a sole practitioner against all personal income.