will changing my username to access my bank affect QB's ability to pull through entries from my bank accounts?

Welcome to the Community, Hekgate. Yes, changing your bank username will likely stop QuickBooks from pulling up new transactions. Because the connection relies on your specific login credentials, the link between the two will break as soon as you change your sign-in details at the bank's website.

To prevent this from happening, let's also ensure to update your username in QuickBooks so it can keep downloading your latest transactions.

Here's how: 

1. Navigate to All apps, then choose Accounting.
2. Select Bank Transactions, then click the account you're changing the username to.
3. Click on the Pencil icon, and select Edit sign-in info.
4. Update the information needed, then click Save to complete the changes.

Once done updating, QuickBooks will recognize your new username and will automatically downloads the latest available transactions.

If you have any further concerns, please feel free to ask. We're here to help.