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共同創業者を合法的に迎え入れる方法:株式、IP、およびベスティング契約について解説

共同創業者を合法的に受け入れる方法:株式、IP、およびベスティング契約について解説

アレクサンドラ・ブレイク, Key-g.com
によって 
アレクサンドラ・ブレイク, Key-g.com
7分読了
法律コンサルティング
4月 07, 2025

Bringing a co-founder on board is one of the most critical steps in the early stages of a startup. However, how to legally onboard a co-founder is not as simple as shaking hands and starting to work. Founders need to be cautious and intentional about the legal framework surrounding their partnership to ensure long-term success and avoid potential conflicts down the road. The process involves various legal agreements, including equity allocation, intellectual property (IP) ownership, and vesting schedules. In this article, we will break down these critical aspects and explain the necessary steps to ensure both legal compliance and fairness in the partnership.

The Importance of Legally Onboarding a Co-Founder

When you think about how to legally onboard a co-founder, it’s easy to focus solely on the excitement of building something together. However, overlooking the legal details can have significant ramifications. A lack of proper legal structure can lead to disputes over ownership, responsibilities, or intellectual property down the road. As a result, securing legally binding agreements from the outset is essential to creating a solid foundation for your startup.

Before diving into specific legal agreements, it’s important to understand why legal onboarding is necessary. A well-drafted agreement can prevent misunderstandings, reduce potential conflicts, and set clear expectations for all parties involved. It also provides a framework for handling issues like the departure of a co-founder or changes in ownership percentages.

Let’s dive deeper into the core components of legally onboarding a co-founder: equity agreements, intellectual property, and vesting schedules.

1. Equity: Defining Ownership and Roles

One of the most critical aspects of legally onboarding a co-founder is determining equity distribution. How much ownership should each founder receive, and what factors will influence the division of equity? This is a question that requires careful consideration, as it will shape the future dynamics of the startup.

Understanding Equity Distribution

The distribution of equity reflects each founder’s contribution to the company, both in terms of initial capital and the long-term role they will play. Generally, equity is split based on a combination of several factors:

  • Initial Contribution: This could include financial investment, industry expertise, or previous work relevant to the startup.
  • Role and Responsibilities: The founder who takes on a more prominent role or provides technical expertise might warrant more equity.
  • Sweat Equity: This refers to the non-monetary contribution of time, effort, and skill. A co-founder who dedicates more time and resources will typically receive more equity.

While equity distribution may seem straightforward, it’s essential to remember that unequal contributions should be reflected in a legal agreement to avoid future resentment or confusion.

Once you’ve determined how much equity each co-founder will receive, you must formalize this agreement. A Shareholders’ Agreement is the primary document to outline the equity distribution, including the rights and obligations of each party. This agreement can also specify restrictions on the transfer of shares, voting rights, and any protections for minority shareholders.

2. Intellectual Property (IP) Ownership and Protection

A co-founder’s role in creating intellectual property can be one of the most significant contributions to a startup. Whether it’s software code, branding, product designs, or even business strategies, IP can be the company’s most valuable asset. Thus, when onboarding a co-founder, it’s critical to address ownership of intellectual property.

Assigning Ownership of IP

To ensure clarity, all intellectual property developed by co-founders during the startup’s existence should be assigned to the company from the outset. In most cases, this involves an IP Assignment Agreement, which legally transfers ownership of any intellectual property to the company as soon as it is created. This agreement ensures that both co-founders and the startup itself are protected in the event of disputes or if one co-founder decides to leave the company.

The “Work for Hire” Doctrine

Under U.S. law, when someone is employed to create intellectual property, the “work for hire” doctrine generally assigns the intellectual property to the employer, rather than the creator. This principle is often included in contracts between founders to ensure that any intellectual property developed during the course of the startup’s operations remains the property of the company.

However, if the co-founders are working in a capacity where they are not considered employees, it’s vital to include a clause that explicitly transfers ownership of the IP to the company. Without this, there’s a risk that a co-founder could claim ownership of critical assets if the partnership dissolves.

3. Vesting Agreements: Protecting the Long-Term Health of the Startup

When learning how to legally onboard a co-founder, another key element to address is the vesting schedule. Vesting refers to the process by which a co-founder earns their equity over time, rather than receiving all of it upfront.

What is Vesting?

A vesting agreement ensures that co-founders remain committed to the company over the long term. Without vesting, a co-founder could leave the company early and retain a significant share of the equity. A standard vesting schedule for co-founders typically spans four years, with a one-year cliff. This means that the co-founder will earn 25% of their equity after one year, and the rest will vest monthly over the following three years.

Why is Vesting Important?

Vesting helps prevent a situation where a co-founder leaves shortly after receiving equity, potentially leaving the company with an equity holder who is no longer contributing. It also ensures that co-founders are incentivized to stay with the company and work toward its long-term success.

Additionally, vesting protects the remaining co-founder(s) in the event that one co-founder fails to deliver on their promises or leaves early. Without a vesting agreement, a departing co-founder could take a substantial portion of the company’s equity with them, potentially undermining the efforts of the remaining team.

The Role of Cliff Vesting

The concept of a “cliff” is another important aspect of vesting schedules. Typically, this first-year cliff means that no equity is vested until the co-founder has been with the company for at least one year. If they leave before the cliff period ends, they forfeit their equity. If they stay for the full year, they vest 25% of their equity, with the rest vesting monthly over the subsequent years.

In addition to equity distribution, IP ownership, and vesting schedules, a few key legal clauses should be included in any co-founder agreement to protect the interests of all parties involved.

Non-Compete and Non-Disclosure Agreements (NDA)

To protect the company’s sensitive information and trade secrets, a non-compete そして non-disclosure agreement 非常に有益な場合があります。これらの条項は、共同設立者が会社の機密ビジネス情報を開示したり、退職後一定期間、競合するビジネスを開始したりすることを禁止しています。

出口戦略と解散

将来を予測するのは困難ですが、共同創業者が袂を分かつことになった場合にどうするか、計画を立てておくことが重要です。A 売買契約 または 出口戦略条項 共同創業者がパートナーシップ解消時に、もう一方の持分を買い取る方法を概説することができます。この合意は、対立を防ぎ、関係が解消した場合に両当事者が明確な道筋を持てるようにするのに役立ちます。

結論

共同創業者を法的に受け入れる方法を知ることは、スタートアップを成功させるための重要なステップです。株式の分配、知的財産権の所有権、ベスティングスケジュールなどの重要な法的側面に対処することで、長期的な成長のための強固な基盤を構築できます。株主間契約の作成、知的財産の譲渡、または公正なベスティングスケジュールの確立など、これらの法的合意は創業者と会社の両方を保護します。

このプロセスは複雑に思えるかもしれませんが、最初から明確な法的枠組みを設けておくことで、すべての共同創業者**が目標と責任において足並みを揃えることができます。**これらの法的合意に時間とリソースを投資することで、将来的に大きな頭痛の種を減らし、スタートアップが成功するために必要な安定性を提供することができます。