To validate addresses in an Excel spreadsheet, download YAddress Excel Add-in to your computer:
Download YAddress Excel Add-in
Once downloaded, open the spreadsheet in Excel, click "Run YAddress" button and follow the instructions.
YAddress Excel add-in uses macros to run address validation. If macros are disabled in your Excel,
you can enable them in File / Options / Trust Center. Click on Trust Center Settings button,
select Macro Settings in the left pane, and choose Enable Macros.