# Investigate a wrong check digit

Read the warning, verify the source value and check again.

Source: https://help.smartfact.ai/barcodebench/guides/wrong-check-digit

Audience: Operator

This lesson uses made-up values. BarcodeBench checks the text received, not the physical print quality, ownership or correctness of a shipment.

## Investigate a wrong check digit

1. **Start a barcode check**

   Start a barcode check.

   Start a temporary session. Values stay on this device and are not sent for a remote lookup.

2. **Enter a code with a wrong check digit**

   Enter a code with a wrong check digit.

   Use this made-up example to see how a wrong check digit is reported. BarcodeBench will keep the value you entered.

3. **Choose how to read the value**

   Choose how to read the value.

   Move to the format choice before asking BarcodeBench to explain the value.

4. **Choose GS1 data in brackets**

   Choose GS1 data in brackets.

   Choose the format that matches the data you are checking. BarcodeBench keeps the original value.

5. **Read the check-digit warning**

   Read the check-digit warning.

   The result identifies the wrong check digit. Check the source record or label before changing your own data.

6. **Return to the exact value**

   Return to the exact value.

   Go back to the input. The previous result is not an instruction to repair the physical label without checking its source.

7. **Enter the checked source value**

   Enter the checked source value.

   For this practice example, enter the known correct value. In real work, first confirm the value with the source system.

8. **Choose how to read the value**

   Choose how to read the value.

   Move to the format choice before asking BarcodeBench to explain the value.

9. **Check the reviewed value**

   Check the reviewed value.

   Check the new value and read the result. BarcodeBench does not silently repair data.

[Watch or practise this chapter](https://help.smartfact.ai/barcodebench/demo?guide=wrong-check-digit&chapter=wrong-check-digit)