I imported my QB file (from PC Quickbooks to QB Online) and the Payee is blank in my imported records.

Let's work together to fix your import issue, @AmberUKUSA.

Before we proceed, I'd suggest checking this article to know the import limitations when moving your QuickBooks Desktop (QBDT) file to QuickBooks Online (QBO): What to expect when you switch from QuickBooks Desktop to QuickBooks Online.

Then, to ensure all data will be imported, you can do the manual import instead of the conversion process. To start, you'll have to delete the transactions you previously imported to avoid duplicates. 

Once everything is fine, you're now ready to do the manual import. Let me guide you how:

1. Secure a copy of the data you need to import in a CSV file, Google Sheets, or an XLS/XLSX file format.
2. Once done, open your QBO account and select the Gear icon.
3. Under Tools, click Import data.
4. Select the box for the specific type of data you need to import.
5. Then, click Browse and select the file. 

For your reference about the process, please check this article: Common questions about importing data to QuickBooks Online.

Also, pulling up reports in QBO is easy. This will let you have a summary of the details you need. You can also filter and customize each report based on your business preferences. 

In case you need additional assistance in importing your QBDT data to QBO, feel free to add a reply below. I'm always here to help. Have a good one.

So there isn't a way for the automated import to include the payee?

Is there a way to have a second set of books that includes past years but closes at the end of Dec 2020 (where the import would have started with missing data).
And then this set of books starts anew?

I don't have time to reimport manually right now.
I'll have to redo everything once I have the numbers I need.

@AmberUKUSA 

Another option, consider purchasing a third party conversion service to include certain other data migrations (e.g attachments, vendor bank details).

OK thanks. I'm trying to save money, so I don't think a third party is viable ... lol. I don't have that many entries per month, so maybe just manually redoing it once I have time is the best way to go.
Sigh, things like this always end up more complicated than they really should be. I wanted to just transfer data as I now have a Mac and use the convenient online version. Not convenient at all any more.

If I purchased the Mac version of Quickbooks (instead of using the online version) is it likely to import more smoothly - including Payees (which seems ilke a basic requirement).

OK thanks. I'm trying to save money, so I don't think a third party is viable ... lol. I don't have that many entries per month, so maybe just manually redoing it once I have time is the best way to go.
Sigh, things like this always end up more complicated than they really should be. I wanted to just transfer data as I now have a Mac and use the convenient online version. Not convenient at all any more.

If I purchased the Mac version of Quickbooks (instead of using the online version) is it likely to import more smoothly - including Payees (which seems ilke a basic requirement).