Unlinking one bank account then add another

It's nice to see you here, @AdamD1791.

Let me help you retrieve First Direct bank transactions and link the Monzo account in QuickBooks Self-employed (QBSE).

If you disconnect the FD account, you will no longer see the transactions, but the data is still available. We can reconnect your account to your company file to retrieve this. To make the account active, repeat the process and turn it back ON. Then, you can connect the Monzo account without disconnecting the FD account.

Here's how:
 

1. Click the profile ⚙ icon and then select Bank accounts.
2. In the search box, enter the name or URL of your bank. Then select Continue. If you've already connected an account before, select Connect another.
3. Enter the sign-in info you use for your bank's website.
4. When you’re ready, select Connect securely.

You can check this article for more details about managing accounts in QBSE: Connect bank and credit card accounts to QuickBooks Self-Employed.

Moreover, you'll want to get transactions in QBSE so you'll have a copy of your transaction's detailed list. Learn from this article how to export into a CSV file. Here's an article for more information: Export Transactions And Get Reports In QuickBooks Self-Employed.

Feel free to get back to me here in the Community space if you need further assistance connecting accounts. You can also post here again if you have any additional QuickBooks-related concerns. It'll be my pleasure to cater to them again. Stay safe, and have a nice day!