I have Online Intuit Quickbooks Advance. Can I add the logo of the company on a custom form style of the Packing slip?

Yes, we can add your company logo in the Custom Form Styles section or Company settings to ensure it appears on the packing slip. Consider me your partner in this, Constantina. 

Please know that customizing the packing slip is not an option at the moment. Nonetheless, you can add your company logo by uploading it either in the Standard default template or within your Company settings.

Once you add your logo to the Standard default template, it will also update in your Company settings.

Before we proceed, ensure that the photo you're trying to attach meets the requirements so you can successfully add it. Here are the specific logo requirements:

• a .gif, .bmp, .png, .jpg, .jpe, or .jpeg file
• smaller than 10 MB
• 24 bits or less in bit depth (or color depth)
• square-shaped since rectangles don't work
• using the standard RGB color space
• convert to an RGB image using tools (such as Adobe Photoshop) if your logo is CMKY-formatted. 

Now, let's add your logo by following these steps.

1. Hover to the Gear icon, then select Custom form styles.
2. Choose the Standard template. Then, select Edit under the Action column. 
3. Go to the Design tab, then select Make logo edits.
4. Select the box with Add a logo +, then the + on the next window.
5. Locate and select the image you want to use. 
6. Select Open. Once uploading is done, choose Save. 
7. Make sure to hit the Show logo option, then Done.

Refer to this article for more information: Add, customise, or remove logos.

After following these steps, you can see your company logo on the packing slip. Here's a sample screenshot for a visual reference.
 

If you're using a different template and have added your logo there, please know it won't show up on your packing slip. As a workaround, we can open your preferred invoice and change its template to Standard, which allows your logo to appear on the packing slip. I've attached a screenshot for your reference. 

Moreover, you can email or print multiple sales forms in QuickBooks Online. This way, you can efficiently manage your sales forms and keep track of your financial transactions in the future.
 
Adding a logo to packing slips strengthens your brand, and with the recommended steps above, we can achieve your goal. If you need further assistance with this, be assured I'm here to help. I wish you every success, Constantina.