Merge from Excel or other spreadsheets onto Avery Labels | Avery.com First, be sure your data in the spreadsheet is arranged in columns. Then, in step 3 Customize On the left click on Import Data and select Start Import/Merge Next, select Browse for File and locate your spreadsheet (Available file types: .xls, xlsx and csv). If you get an error, try saving your file as a .csv and re-upload.