Instead of a standard HTML invoice, create a highly branded, interactive landing page for each invoice that includes a countdown timer for early-bird discounts.
If you want, I can:
: Not publicly disclosed
modules.invoice-builder-module-for-perfex-crm-v1.0.0.zip into the modules folder and extract it.
If prompted, click Upgrade Database to ensure the module's tables are correctly set up in your system. Technical Specifications Invoice Builder Module for Perfex CRM | PDF - Scribd invoice-builder-module-for-perfex-crm-v1.0.0.zip