Hi Garner,
You cannot void a customer invoice that has had activity, such as applied deposit. You will need to enter credit memo and apply to invoice to close it. Please refer to Article 19469 - How to void customer invoices entered through Accounts Receivable - in Sage Knowledgebase.
Thank you.

Janice,

Thank you very much for responding but I am having trouble locating the article. Could you let me know how to find it. Thanks in advance!

To search the Knowledge Base, go to support.na.sage.com and login. Select the "Search" option listed near the top. In the center of the screen where is say "Seach the knowledge base" type in the number or words you are searching form. In this example, type 19469 and select the look up. The results will list below the search - "How to void customer invoices enter through Accounts Receivable: displays.
If you are still having issues using the Knowledge Base, please call 800-447-5700 and a support analyst can assist you.
Thank you,
Coleen