This article explains how to modify Special Pricing Schedules.
1. Open WMS.
2. Go to Sales register.
3. Open Actions > select Special Pricing.
4. Search existing Special Pricing by Customer, Item or Date.
5. Select Special Pricing.
6. Select ''Edit'' or "Cancel".
7. Make the changed and select.
Special price uses best price , lowest price.
If the same Item involved in two or more SPS setups then if any setup price set to 0 price and/or 0 discount then WMS will default to Base Sell Price. To resolve this issue please amend/delete zero value line or put 100% discount to give for free to re-calculate correct price.