I appreciate your time for reaching out in the Community for assistance, @saranyaac, and I'm here to ensure you receive the appropriate support in relation to your concern.
While the Community can help you with specific questions and troubleshooting solutions, there are certain matters for which only our Intuit Developers can provide specific information.
If you have questions or concerns about line item limitation when creating an invoice through API, we recommend that you post your question on our Intuit Developer Community.
This forum is where developers, product experts, and engineers can help you with software, QuickBooks API concerns, product integration, or developer license-related questions. They have access to specialized tools and resources to provide you with the correct information.
To post your question, follow these steps:
- Go to our Intuit Developers support page.
- Choose General Questions.
- Select Ask a Questions, then tap Sign in or Create Account if prompted.
- Type your concern in the box, then click Post a question.


Nevertheless, you can customize invoices, estimates, and sales receipts and learn about usage limits in QuickBooks Online.
If you have any additional questions about managing invoices, please don't hesitate to reach out to me. I am always here to help.