Employment status is often considered as a way to reduce fixed costs. One countermeasure would be to reduce the ratio of full-time employees and switch to contract employees. On the other hand, there are also options to consider non-direct employment, such as temporary workers (outsourcing) and contract workers (subcontractors), which are ways to obtain business results by signing a contract with a company that dispatches human resources or a company that provides services. These are required by law to conclude a contract with a corporation. Temporary employees and contract employees naturally have an employment relationship with temporary agencies and contracting companies.
A contract with a sole proprietorship is a form of receiving services from individuals that has been attracting attention recently.

[What are the services of sole proprietorships]

Generally speaking, it means that the individual providing the service becomes the business owner and takes some kind of response to the company. The relationship between drivers and companies that provide online taxis, motorbike taxis, delivery services, etc. that are now becoming an indispensable part of daily life is actually a contract with a sole proprietor. Since this is not employment, no wages will be paid under this contract. Since you will be paying for the services provided, the payment method will be agreed upon in the contract. Proof of the service performed is also required.
A partnership agreement with a sole proprietorship specifies the content of the services to be provided, the compensation for the service, the working method, the rights and obligations of the company and the sole proprietorship, as well as the handling of confidentiality obligations, penalties in the event of violation, and the concept of contract renewal. Even if you are an individual, you are not an employee, so company rules cannot be applied, so everything must be clearly stated in the contract.

[Difference from employment]

The biggest difference from employment is that employment is based on labor law, but contracts with sole proprietorships are for the provision of services, that is, sales contracts, so they are based on civil law and corporate law. Participation in social security, payment of wages above the minimum wage, payment of overtime wages, payment of religious festival allowance, payment of retirement allowance, etc. required by labor law do not apply to contracts with sole proprietorships. On the other hand, in a contract with a sole proprietorship, the price will be set based on the interests of both parties, so there is a high possibility that the wage will be higher than if you were hired. Also, since payment is based on results, it becomes difficult to deal with areas that would normally be managed, such as discipline and confidentiality. Penalties for violations by sole proprietors are not a written warning or dismissal, but rather a claim for damages or the cancellation of a contract, so it can be said that it is difficult to hope for improved results through training and education such as detailed guidance, evaluation, and salary increases.
Even so, the reason why you are considering contracting with a sole proprietor is because you will not incur any costs unless you ask them to provide services. Also, since it is not employment, there are no restrictions on the type of business that can be entered into with a sole proprietorship. However, since we are free individuals, we may contract with other customers, so depending on the situation, there is a non-zero possibility that important company information may be leaked or misused. It can be said that whether or not this is an option will be determined by the kind of relationship you want to provide the service.