Hi, QB imported about 3 months of my most recent transactions, but not the rest.

Let's make sure to import all your bank transactions, kilowatts.

May I know what's the name of your bank? QuickBooks downloads the last 90 days of your transactions depending on your bank once you connect it for the first time. You'll want to do a manual update to refresh the connection between your bank and QuickBooks Online (QBO). To do so, you can follow the steps below:

1. Go to Banking from the left menu.
2. Select the Update button in the upper right.
3. Select Update Now.

Moreover, you can also manually import transactions in QuickBooks. This lets you enter older data into the program. Learn from this article for your reference: Manually Upload Transactions Into QuickBooks Online.

Fill me in if you have any concerns with your bank transactions. I'd always be right here to help you out.

@Anonymous 

Another option, use MT Online or one of the converter tools (e.g csv2qbo) as a workaround.

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