I am unable to add tax to my invoice lines through the app, it use to give me a drop down box to select 20%vat but now it doesn’t and I am unable to complete an invoice

Hello there, @craig70.

Let me share some troubleshooting steps so you'd be able to add tax to your invoice using the mobile app.

First, let's make sure that  your mobile app is updated-to-the-latest version. This ensures that the program works at its best behavior.

1. Open the App Store on the iPhone or iPad.
2. Locate the QuickBooks app then tap the “Updates” button.
3. Wait for updates to load, then tap on Update All found at the upper right corner of the screen.

Once complete, let's make sure to enable the taxable option when adding products and services to an invoice. This way, it'll take out taxes after clicking the Save option. Here's how:

1. Open the QuickBooks mobile app.
2. Create an invoice.
3. Add a product or service and make sure to enable the Is Taxable option.
4. Press Add.
5. Choose the sales tax. 
6. Hit Save.

In case the sales tax amount still don't apply, I recommend logging in to your account using the web browser. Please check if the invoice transaction you created shows a sales tax.

If it works fine, please proceed with contacting our QuickBooks Support Team. One of them will be able to take over and assist you further with the mobile app problem.

Feel free to drop a comment below if you have follow-up questions about sales tax calculation. I’m always here to help.

Thank you for taking the time to reply, my app is up to date and I get to point 5 ‘select tax’ where there are no options and it says ‘add tax rate’ I have been through the options of adding a vat@20% option but when I go back to the invoice and try to add the tax it is not there and asks me to ‘add tax rate’ again?

I can see the normal tax options and the tax option I have just created on the web just not on the app. 
I have attached an image of what the app shows when I press on tax code. 

I appreciate you for getting back to us, @craig70.

Let's refresh your mobile app's data. This ensure that the information from the regular browser is sync with your mobile app. You can use the screenshot below as reference.

If refreshing the app doesn't work, try uninstalling and reinstalling the app to resolve unexpected behavior on mobile devices, and ensure updated security settings are downloaded. You can read through these articles for more detailed steps:

• How to download the QuickBooks Online mobile app

• Compare mobile app features

Get back to us here if you have other questions or concerns. I'm always here to help

I have just deleted and downloaded the app again and I have refreshed the data like you suggested but still no luck, I am still unable to select a tax rate to add to my invoices off the app

We want this resolved as much as you do, Craig70. 

I suggest reaching out to our customer care support so a live agent can take a better look at this. Let me guide you:

1. Go to the Help & Feedback tab, then click Help and Support.
2. Click Contact Us.
3. Enter "Unable to add tax on the invoice lines" in the description field, then click Let's talk.
4. Select either Chat or Callback. 

In the meantime, you can create the invoice through the browser. 

Feel free to visit us anytime if you have other concerns. We're one post away. Keep safe!