# Do not allow change in rates of transacted Lots

**YouTube:** [How to Restrict Editing of Already Transacted Lots/ Batches in Purchase?](https://www.youtube.com/watch?v=dKVg7vI4K6I)

## How to Restrict Editing of Already Transacted Lots/ Batches in Purchase?

This tutorial explains how to enable a setting in Logic ERP that **prevents modification of rates** for lots that have already been transacted, ensuring pricing consistency and data integrity.

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### **Enable the Setting in Logic Admin**

* Open the **Logic** installation folder.
* Launch **Logic Admin**.
* Go to **Global Settings**.
* Navigate to the **Purchase** tab.
* Enable the checkbox labeled: **“Do not allow change in rates of transacted Lots”**.

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* Click **Save** to apply the changes.
* **Restart** the Logic ERP software to activate the setting.

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### Implement **the Restriction in a Purchase Voucher**

* Open Logic ERP and create a **Purchase Voucher**.
* Select a lot (e.g., **Lot 1299**) and **modify its rate**.
* Save the voucher.

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### **Attempt to Change the Rate Again**

* Try to create another purchase entry for the **same item and lot**.
* Press **F5** to edit/view the rate for the selected lot.
* You will observe that the **rate cannot be changed**, as the restriction is now enforced.

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### **Summary**

This feature ensures that once a lot has been used in a transaction, its rate is locked to maintain consistency across all purchase entries. It is especially useful for audit control and preventing unintentional pricing discrepancies.