Do you have an error code 509 when linking a Fidelity account? How did you fix it?

Hi there, castagrueso.

Please note that we've received a similar issue about having an error code 509 when linking a Fidelity account to QuickBooks Online. I'll ensure you'll be routed you to the right support team to assist you further on this matter.

I recommend contacting our QuickBooks Online Support Team as they're the best support group for such inquiries as they can request account information. This allows them to document your concern and see the number of affected users on the said issue.

Here’s how to get in touch with them:

1. Log in to your QBO account.
2. Click the? Help button at the top right corner.
3. Go to the Search tab, then select Contact Us.
4. Enter a brief discussion with your concern, then click Continue.
5. Choose a way to connect with us.

In case you need steps on how you can review your imported or downloaded data by matching or adding them to avoid duplicate ones, you can read this article: Categorize online bank transactions in QuickBooks Online.

You can always add a comment below if you have any other concerns about connecting a bank account in QBO. I'm always here to help you further, castagrueso. Take care!

@castagrueso-gmai 

You can use MT Online or one of the converter tools (e.g csv2qbo @ $60 one time license) as a workaround.

https://www.moneythumb.com/?ref=110