I am an AI language model and can provide you with some general information on this topic. However, please note that I am not a legal professional, and it's always advisable to consult with a business attorney or relevant authorities for specific legal advice.

When it comes to online businesses in the USA, the need for a separate business license in each state where you sell goods or services can depend on various factors. Here are some key considerations:

1. Nexus: Nexus refers to a significant connection or presence in a state that triggers a tax obligation. In the context of online businesses, nexus can be established through various factors, such as physical presence (e.g., having a physical office or employees) or economic presence (e.g., reaching a certain sales threshold or having affiliates in a state). The concept of nexus is crucial in determining whether you need to obtain a business license in a particular state.

2. Sales Tax: If your online business involves selling tangible products, you may be required to collect and remit sales tax in states where you have nexus. Each state has its own sales tax laws and thresholds for determining nexus. For example, in the landmark Supreme Court case South Dakota v. Wayfair (2018), the court ruled that physical presence is no longer required for states to impose sales tax obligations on remote sellers. Instead, economic presence can be sufficient to establish nexus.

3. Professional Licenses: Certain professions or industries may require specific licenses or permits to operate legally. These licenses are often regulated at the state level and can vary depending on the nature of your business. For example, if you are running an online pharmacy or providing legal services, you may need to obtain additional licenses or certifications specific to those industries.

It's important to note that the requirements for business licenses can vary significantly from state to state. Some states may require a general business license for all businesses, while others may have specific licenses for different industries. Additionally, local municipalities or counties may also have their own licensing requirements.

To determine your specific licensing obligations, you should consult the Secretary of State's office or the appropriate licensing agency in each state where you plan to conduct business. They can provide you with the most up-to-date and accurate information regarding the licensing requirements for your industry.

Furthermore, it's advisable to consult with a business attorney or tax professional who can guide you through the legal requirements and help ensure compliance with all relevant state and local regulations.

Remember, this is only general information, and the specific requirements for your online business may vary based on factors such as the nature of your business, the states involved, and any industry-specific regulations.