I need to import my client list of nearly 13k entries. Everything is set up in Classic custom fields (tried the new custom fields first). I did one import of my clients’ names and email addresses. Then I’ve tried to export to update the batch, yet it doesn’t export the custom field codes that I’ve made. I made one client with all the custom fields populated, thinking maybe that will force the columns to be made. Only 3 columns end up exporting. Someone please tell me there’s a simple workaround to this issue. I need a lot more details for my clients other than name and email. I made custom fields specifically so it will be possible to export directly from my website to automate the invoicing process. Thanks in advance
Pretend you are coming to do batch update this will bring out all columns to be updated and then remove all the other update related fields such as the “key” (universally unique identifier) and then start a batch process to import that sheet.
I would still test this with a small sample first, maybe 5 or 10 entries, before running the full list import.
Hello @ruby33,
Welcome to the forum.
Before “exporting”, you should first Upgrade these classic custom fields. Then it should be business as usual.
Also, you need to migrate the custom field settings first before migrating your data
So, just coming back to tell you I found the solution. Really silly tbh, but didn’t realize that the boxes had to be ticked next to the clients and then click Batch Update. It confused me because it would still copy 3 columns of text from all the clients on the page. 
Is there a problem using the Classic custom fields? I don’t want to run into issues later on, of course.
There isn’t any problem so far, it’s just that they have been labelled as obsolete feature for quite a while now.