sales tax change mid transaction

[RGWELD]

Has anypne had experience where an online order has had the tax amount change after customer checked out? We have had a few times where the customer pays, and then shopify 'updates' the tax information after the fact and then charges then again. The initial charge is voided and a second charge is authorized after the fact. This has happened to us several times and the customers are always angry- and rightly so. they think we are over charging them after the fact. When i ask shopify about it I get the most ridiculous uneducated answers from their support- one even told me that maybe my state (California) had changed their tax rates mid transaction...

Any real advice would be appreciated. 

[shahrozbabar5 · Accepted solution]

Hi @RGWELD,

This issue with Shopify updating the tax amount after a customer has checked out is frustrating and understandably causing customer dissatisfaction. Here's a concise breakdown of possible causes and solutions:

### Possible Causes:
1. **Third-Party Apps**: Sometimes, tax apps or third-party integrations can update the tax calculation after the transaction.
2. **Address Validation**: Shopify may update tax rates if it receives updated address information post-checkout.
3. **Shopify Tax Calculation**: Shopify’s tax engine could be recalculating taxes if there’s a delay or error in the initial calculation, possibly due to server-side issues.

### Solutions:
1. **Audit Third-Party Apps**: Check if any tax-related apps are integrated with your store and causing recalculations. Disable them temporarily to test.
2. **Manual Tax Override**: If the issue persists, consider setting up manual tax rates for your state to avoid automatic updates.
3. **Clear Communication**: Notify customers at checkout that taxes are estimated and may adjust slightly based on address validation, but that double-charging is not your intention.
4. **Shopify Support Escalation**: Request to escalate the issue to a higher level of Shopify support or a technical specialist who can investigate the backend processes and resolve the problem.

If it resolves your issue, please mark my answer as a solution or if you still need assistance, let me know. Thank you.