Thanks for your response @MirriamM .  Sorry for the delay, but I didn't receive an email alert as I normally do.

I'm afraid I can't precisely answer your question.  I have imported older bank statements via .csv and more recently QB has been connected to my bank.  I have also edited or added individual transactions manually.

I tried to resolve this by deleted the transactions that are being duplicated.  I also tried excluding them.  Now everything is messed up and I can't reconcile.  If I put back the deleted transactions into the credit card to reconcile, the current account will show a duplicate.

Sorry for the lack of clarity, this is the bet I can do.