Shift Loyalty and Deposit Calculations to Pre-Tax Logic

I am writing to request a change in how the system handles tax calculations when Loyalty points or Deposits are applied. Currently, the system calculates these payments after taxes and fees have been applied to the full subtotal. This logic results in a "tax on tax" effect or a discrepancy that overcharges the customer compared to the actual remaining balance.

The Problem: When a deposit or loyalty credit is treated as a post-tax payment rather than a pre-tax deduction, the customer ends up paying taxes and fees on a value they have already partially cleared.

Mathematical Proof of Discrepancy:

• Transaction Total: $100.00
• Applied Taxes & Fees: 8.88% Tax + 3.12% Card Fee.
• True Gross Total: $112.28

1. The Deposit: The customer makes a $10.00 deposit. Including tax and fees, they pay $11.23.
2. The Math: Total ($112.28) - Paid ($11.23) = $101.05 (Expected Balance).
3. The System Issue: Currently, Linga shows a balance due of $101.97.
4. The Discrepancy: This creates a $0.92 – $0.97 error on a small $100 order.

Scalability Concern: This error scales significantly with larger transactions. For a $10,000 banquet with a $5,000 deposit, the calculation error grows to $457.85. This is a significant financial discrepancy that is difficult to explain to a merchant or a guest.

Proposed Solution: Update the calculation logic so that all Deposit and Loyalty operations are deducted from the subtotal before taxes, additional fees, and card charges are calculated. This ensures that taxes are only applied to the remaining taxable liability, maintaining accounting integrity and preventing double-charging of fees.