iCloud stores your spreadsheets and keeps them up-to-date on your computers and iOS devices that are signed in to iCloud with the same Apple ID. You always see the latest version of your spreadsheet, no matter where you made your last edits.
For seamless syncing of spreadsheets, use iCloud Drive, iOS 8 or later on your devices, and OS X 10.10 or later on your Mac computers.
You can also use Numbers for iCloud to create and edit Numbers spreadsheets using a supported web browser on a Mac or Windows computer.
Open System Preferences (from the Apple menu at the top-left corner of your screen), then click iCloud.
Sign in using your Apple ID, or request an Apple ID, then sign in.
Important: If you forgot your Apple ID or its password, you can recover it on the Apple ID website. Though you can have more than one Apple ID, it’s not recommended. iTunes Store and App Store purchases made with one Apple ID can’t be merged with those made using another Apple ID.
Select the iCloud Drive checkbox.
Click Options next to the iCloud Drive checkbox, then select the Numbers checkbox.
When iCloud is turned off for Numbers on your Mac, edits you make or new spreadsheets that you create aren’t saved to iCloud, and spreadsheets that are newly created or changed on your devices or on your computer aren’t available in Numbers on your Mac.
Spreadsheets you create using Numbers for iCloud are automatically available in Numbers on your Mac and iOS devices that are set up to use iCloud—and vice versa. If you create a spreadsheet using Numbers on an iOS device or a Mac, the spreadsheet appears automatically in Numbers for iCloud.
Make sure you’re signed in to iCloud on your Mac and iCloud Drive is selected (in iCloud preferences in System Preferences).
On your Mac or Windows computer, go to iCloud.com, then sign in using the same Apple ID.
Click Numbers.
See Numbers for iCloud Help for more information about using Numbers for iCloud.
Here are a few things to keep in mind about using iCloud to manage your spreadsheets across devices:
If you edit then close a spreadsheet when you’re not connected to the Internet, you see a cloud icon next to the spreadsheet thumbnail in the Open dialog on your Mac. The next time you connect to the Internet, the edited spreadsheet is saved to iCloud.
If you edit a spreadsheet on multiple computers or devices and don’t allow time for your edits to sync, you will see conflicts. If you do get a conflict, you can choose to preserve any or all of the versions. (This applies only to spreadsheets not shared with others.)
If you delete a spreadsheet that someone shared with you, it’s deleted from your iCloud Drive and from Numbers on all your devices. You can click the shared link again to add the spreadsheet back to your iCloud Drive, where it’s again available on all your computers and devices with iCloud turned on.
If you use folders to organize your spreadsheets on one device, the same folder organization applies on all your devices.
If you add a password to a spreadsheet on one device, it’s required to open the spreadsheet on all your devices.
If you’re using older versions of Numbers and macOS on other computers, or you haven’t upgraded your iCloud account to use iCloud Drive, syncing won’t work in all cases. See the Apple Support article Use iWork with iCloud Drive for more information.