Should all selected transactions be imported from a PayPal account or does it only import three months even when twelve months have been selected?

Glad to see you in the Community space, @andy71.

Paypal or any bank connection will only allow up to 90 days worth of transactions when importing them via direct connect. 

You can still import older transactions by manually uploading them into QuickBooks through WebConnect. You can refer to this link on how: Manually upload transactions into QuickBooks Online.

Just in case you want to use bank rules to categorize your PayPal transactions, you can check out this helpful article: How to set and use banking rules for downloaded transactions.

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