Hi there amy-timminsnorth,
It's important that all your transactions are correctly entered for your books to be well-balanced. QuickBooks Online is a great tool able to import transactions from various bank sites so you can easily add them to your books. I can point you in the right direction for assistance with bank connections.
For errors with bank connections, I recommend following the steps in this article. There are some general steps that could help with most errors, as well as links for steps for specific, common errors seen.
If you have any other questions, feel free to reach out here.
