[A] To add an approval rule for an invoice, go to the "Approval module" (1), click on the "Settings" tab (2) and click on Add New Rule(3).
[B] The drop-down list has three options: Credit Limit, Company and Amount. Select the type of Approval to be added.
[C] On the next screen, click on the Document Type list and select Sales Invoice. Add other details about upper or lower bounds, company name and who to ask for approval.
[D] You can keep the company name field blank if the rule is applicable to all the companies.
[E] Click on Save Rules. The rule gets added.
Keywords: sales invoice approval rule, invoice approval, approval for sales invoice