To comply with the requirement to list both the cash price and the credit card price separately, including a 3.5% processing fee, you can manually add this fee as a separate line item on your sales invoices. Here's a brief guide on how to do this effectively:

1. In your existing sales invoice, create a new line item for the credit card processing fee.
2. Enter a description for this line item, such as "Credit Card Processing Fee".
3. Manually calculate the 3.5% of the invoice cash price and enter this amount in the "Amount" column. For instance, for an invoice of $100, the fee would be $3.50 ($100 x 3.5%).
4. Select an appropriate revenue account for this fee in the "Account" column and ensure no taxes are applied to this fee by selecting "No Tax" in the Tax column.

For a step-by-step guide and more detailed instructions, please refer to our article on charging credit card merchant fees on sales invoices: How to charge customers credit card merchant fees on sales invoices.

Furthermore, to facilitate different invoicing needs, including the ability to customize invoices for various situations, you might find our article on using Invoice Styles within Sage 50 helpful. It outlines how to create and switch between different types of customized invoice forms, which could be particularly useful for presenting the invoice cash price and credit card price distinctly. For more information, please visit: How to customize forms and invoice styles.

If there's anything more we can help you with or if you need further clarification, please don't hesitate to reach out.

Warm regards,
Erzsi