How can you only add one month of bank transactions at a time?

Good to see you here in the Community, jdsjlatta. I'd be happy to help with your inquiry about adding bank transactions in QBO. 

Rather than downloading all transactions at once through online banking, you can import transactions for a specific period by using a CSV (Excel) file. This allows you to import just one month's worth of bank data at a time. I'd be glad to provide some guidance. 

First, you can ask for or download a copy of your transactions from your bank's website. Follow the format in the screenshots or the steps in this article as your guide: Format CSV Files In Excel To Get Bank Transactions Into QuickBooks Online

After that, here are the steps on how to import the file:

1. Go to Transactions, then select Bank transactions.
2. Select the blue tile for the account you want to upload the transactions into.
3. Click the drop-down list beside Link account▼ and select Upload from file.
4. Select the file you downloaded from your bank. Then, click Continue.
5. Choose the account you want to upload the transactions into. Then, select Continue.
6. Follow the onscreen steps to match the columns on the file with the correct fields in QuickBooks. Then, select Continue.
7. Select the transactions you like to import and choose Continue.
8. Click Yes, then select Done.

For additional guidance and references when importing and managing banking transactions, I'll share these articles as well:

• Fix Bank Upload Errors In QuickBooks Online
• Categorize Online Bank Transactions In QuickBooks Online

Let me know if you have any other questions as you put in your banking transactions, jdsjlatta. I'd be happy to provide additional guidance on using the online banking features in QuickBooks Online.