Why cant i save my invoice/estimate whenever i add on shipping fees

Congratulations on making your first post here, @thepartyheavenuk. 

I understand your need to save your invoices/estimates with the shipping fee. I'll lay down solutions to help you keep them for your tracking purposes.

Let’s start by using a private browser to access your QuickBooks account. This doesn't retain local files, so this helps in ruling out the possibility of a webpage issue.

Here are the shortcut keys:

• For Firefox, press Ctrl + Shift + P.
• For Chrome, press Ctrl + Shift + N.
• For Safari, hold down Command + Shift + N.

Afterwards, log in to your account and save the transaction. If this works, you’ll need to clear the browser's cache. By doing this, it’ll remove the history or built-up cache in your default browser, so you can start with a clean slate. You can also try switching to other supported browsers as an alternative.

If you’re still experiencing the same issue, I’d recommend contacting our Support Team. From there, one of our representatives can pull up your account and investigate further. Please also take note of our support hours so we can address your concerns on time.

Here’s how:

1. Go to the Help (?) icon.
2. Select either of these to start: Assistant or Search.
3. Choose between chat or call us.

I’ve included this article about modifying your sales forms: Customise invoices, estimates, and sales receipts in QuickBooks Online. This will walk you through adding specific data and improving your business communications.

Once done, you’ll want to read about recording invoice payments in QuickBooks Online. It contains the instructions together with a short video that will guide you through receiving the payments to balance your accounts.

Know that you're always welcome to get back to me anytime. I'll be more than happy to have you here again. Take care.