Tally Prime 7 Invoice Customization

I have a sales invoice format written in TDL that runs smoothly on Tally Prime Release 2.1. The layout already contains several custom fields and embeds special calculation logic that we rely on daily. As we are moving the whole environment to Tally Prime Release 7, this invoice must be migrated—function-for-function, field-for-field—so everything prints and behaves exactly as it does today. No extra features are needed; the task is strictly a compatibility redesign so the invoice renders flawlessly in the new release without touching or corrupting any of the existing accounting data. Deliverables • A TDL file (or set of files) fully compatible with Tally Prime 7 that reproduces the current invoice’s custom fields and calculation logic • Clear import / load instructions and any required configuration notes • A quick validation session (remote or recorded) showing the invoice working inside Release 7 with sample data drawn from our live company Acceptance criteria The migrated format must load without errors, print identically to the original, and calculate every figure exactly the same across multiple test vouchers.