I had a credit card number change in december. Since then none of my transactions have imported. I tried to relink the account but its not working. any ideas?

Hi there, @atf3333, 

Thanks for visiting the Community. I'm here to help ensure you're able to connect your bank again. 

When you update your bank and credit card account information on your bank's website, you also need to update it in QuickBooks to sync your transactions. I'll show you how: 

1. Select the Profile icon, then select Settings.
2. Click Bank accounts. 
3. Click the Plus (+) icon, then 
4. Search for your bank by name or URL.
5. Enter the sign-in info you use for your bank's website, then select Sign-in when you're ready. 

Once done, you will see all your recent transactions. You can categorize them to make sure they're added to your books. 

For future reference, read through this article in case you'll encounter bank errors while reconnecting your bank: What to do if you get a bank error or can't download transactions in QuickBooks Online.

I'll be here if you still need help with adding your bank. Have a great day.