I would guess that it would double it up, but I really don't know. Save a copy of your income tax return using another name - maybe with TEST TEST TEST in the file name - open it up, import, and see if you have a duplicate.
If you don't then go back over to your live file and import the new 1099.
If you do have a duplicate, go back to your live file, undo the import - "File" > "Remove imported Data" > select 1099 to reverse - then import the new 1099.
Of course you should cruise back through any areas where the 1099 information has changed, just to see if there's anything you need to do.
Tom Young
