'An error occurred lodging pay event Error: 10, Pay Event has reached retry limit.' Our STP is now activated and working but it seems we tried too many times! Any ideas?

Let's perform some troubleshooting steps to get this sorted out, userjimmy-donohue.

It's possible there's a problem with the online (cloud) software provider's system or there was an error communicating with the ATO on our end. To resolve this, try lodging the event later. or after an hour. If the same thing happens, try signing in to your account using a private or incognito window. This mode doesn't use the existing cache data and helps us confirm browser-related issues. Here's how:

• For Google Chrome browser: Ctrl + Shift + N
• For Mozilla Firefox browser: Ctrl + Shift + P
• For Safari browser: Command + Option + P

Then, try lodging the pay event again. To resolve several of the common issues when getting started with Single Touch Payroll, see the Single Touch Payroll - Troubleshooting errors article. 

If it works, go back to your regular browser and clear the cache to delete those temporarily stored files and browsing history. The overtime collection of data can create corruption, however, removing this should fix the issue. You can also use supported, up-to-date browsers to roll out the possibility of a browser-related issue.

If the problem persists, I'd suggest contacting our Customer Support Team. They'll pull up your account in a secure environment and investigate what's causing this issue. Here's how:

1. Go to the Help icon on the top right. 
2. Enter your concern in the search field.
3. Choose Talk to a human.
4. Click the OK. To get you to the right human, in a few words, tell me what you need help with option and tap I still need a human. 
5. Press Contact us.
6. Tick Continue. 
7. Choose Message an agent.

Feel free to visit our Help Article page for more insights about managing your business in QuickBooks. 

I'd like to know how you get on after trying the steps or after containing our support, as I want to ensure this is resolved for you. Just reply to this post and I'll get back to you. Take care always.