Good day, Adrian. Let's ensure that Santander Bank will update in QuickBooks Online (QBO) so you can continue your daily banking tasks.
Before anything else, I'd like to know if a specific error message is shown on your end.
There are various reasons why your bank isn't updating in QBO.
Firstly, the connection between your bank and QBO has expired and must be established and reauthorise your bank account for a further 90-day period. Then, disconnect it and establish the connection again.
Secondly, there's an issue on your bank's end. To confirm this, you can log in to your bank's website and check system maintenance notifications. If you see one, you can contact them to seek advise on the best course of action to take.
Lastly, if the error shows "You're unable to update your account, please try updating again later." This issue can be resolved within 48 hours.
Feel free to read this article for more info: Fix bank errors in QuickBooks Online.
If the error persists after performing the troubleshooting steps, I recommend contacting the QBO Care Team to further isolate this issue. Then, review your bank connection in QBO and find a fix.
Additionally, you can read this article if you want to place your bank transactions to the correct accounts automatically: Set up bank rules to categorise online banking transactions in QuickBooks Online.
You can always return here if you have additional questions about updating your bank connection in QBO. We'll be willing to lend a hand. Keep safe, and have a good one.