I understand the importance of showing the SKU to your invoice forms, @cirrusmarketing. Rest assured, I'm here to guide you to show this and achieve your goal.

You'll need to set up an SKU on each product on the Products and Services page for it to show in an invoice.

Here's how:

1. Go to Sales, then select Products & Services.
2. Find a product and click Edit on the Action column.
3. Fill in the ID Code you want in the SKU textbox field.
4. Hit Save.

Repeat the steps for each product or service to which you want to add SKU. Create an invoice and fill in each line item with your products. It will automatically show in the SKU column if you have enabled it from the settings as my colleague, @AlverMarkT, has provided.

If the ID code still doesn't show in the SKU column, we'll need to clear your browser's cached data to ensure your browser is running in the best condition for QuickBooks Online.

For Google Chrome browser, here's how:

1. Press Ctrl+Shift+Delete while on your browser.
2. Select only the Cached images and files.
3. Set the time range to All time.
4. Click Clear Data.

If you're using a browser other than Chrome, refer to this link as it shows the steps for each browser: Clear cache and cookies to fix issues when using QuickBooks Online.

I'd be glad to help you with any concerns besides the SKU not showing on your invoices. Let us know by commenting below.