Thank you for reaching out to the Community space, @fmkport. I appreciate you taking the time to explain the situation clearly. I'm here to help guide you both through the process of granting you the necessary access. Let's dive into the details and get this sorted out.

In QuickBooks Online (QBO) Advanced, the Custom form styles feature is exclusively accessible to users with administrative roles. This is to ensure only authorized personnel can modify essential customer-facing documents.

To grant you access to this feature, your master administrator needs to add you as a company admin to the QBO account. Here's a detailed step-by-step guide

1. Go to Settings and select Manage users.
2. Select Add user, then enter the user’s name and email address.
3. Hit the Roles dropdown, then select the Company admin role.
4. Review the features this role gives access to.
5. Click Send invitation.

Please note that special characters aren’t allowed other than a period in the user’s name. To get a comprehensive guide of the process, check out this article: Add and manage users in QuickBooks.

This information should help your master admin to authorize you to customize forms in QBO, @fmkport. Our primary objective is to ensure consistency and professionalism in your financial communications. Should you require additional guidance or have further inquiries, indicate so in the comments below.