Why is the automatic calculation of taxes sometimes wrong? How can I resolve an event that adds an incorrect fraction to the tax amount?

Thank you for posting here in the Community, @user113.

I can share some clarification about the taxes in QuickBooks Online.

The system creates a set of GST/VAT codes automatically based on the information we receive from your state agency. If there's a need for you to correct the tax amount, we recommend setting up a new rate instead of updating an existing GST code.

The previous rate may have been used on prior transactions, and adjusting it could affect your sales tax tracking. To add a new one, here's how:

1. In the Tax Centre, select Add Tax. 
2. Choose which type of tax rate you want to set up. 
3. Enter the details of your tax rate. If you need help with this screen, select the help button (yellow question mark).
4. Select Done when finished.

I've also included some articles in case you need more ideas about GST in QuickBooks:

• How do I set up sales GST/VAT rates and use them on forms? (International QBO)
• FAQ for GST in QuickBooks Online
• Applying Sales Tax to Transactions and Sales Forms

Let me know in the comment section below if you have any other questions. Have a great day ahead.

Sorry for my explanation.

Tax rate is settled correctly.(7%)

$375*7%=26.25, why it shows 26.26?

This occurs when i make invoice.

Thanks for the details, user113.

The tax rates are multiplied by line item. Let me use the screenshot you attached as an example. Let's say 7% of $187.50 is 13.13, and on the other line item you have the same amount and rate and it's equal to 13.13. Hence, the GST @7% on $375.00 is 26.26. 

To help you look into the list of rates and manage them, you can check out your Sales tax centre. Just click the Taxes menu and click Edit GST. Then, Edit rates. You can click on a rate to see how they are applied to a sales or purchase transaction. 

My colleague attached articles that will help you handle sales taxes. You can use them as a reference. For further help, you can check out our Community Help articles. 

Always know that we're always available 24/7 so you can post and reply to use anytime. You take care and have a great day!

Sorry again.

How to set up calculate without rounding up the amount?

187.5*0.07=13.125 

Hello there, user113.

QuickBooks Online (QBO) is set to calculate tax rates by multiplying the amount and the rate per each line item while making sure it qualifies the standard set by your state. At this time, there isn't a way we can modify the calculation settings. 

If you need to know more about managing GST in QBO, you can visit the articles shared by my colleagues above.

Feel free to drop me a reply below if there's anything I can help you with. Wishing you all the best!

Did you manage to sort this. I'm having the same issue on random invoices. All of a sudden it seems to calculate the VAT wrong.....any ideas why?

We calculate VAT based on the data entered in your account, 1231 4579 9803 299.

If you're seeing incorrect calculations, make sure to check your sales tax settings. If it's correct, I recommend contacting our QuickBooks support. They will be able to check your account and identify what caused the error.

1. Go to the Help icon.
2. Select Talk to a human.
3. Enter "Talk to a human" again in the search bar.
4. Choose I still need a human, then click Contact us.
5. Select Get a callback or Send a message to start a conversation.

Check put these articles for more information on how QuickBooks handles sales tax:

• How do I set up sales GST/VAT rates and use them on forms? (International QBO)
• Applying Sales Tax to Transactions and Sales Forms

Let me know if you have other questions.