For Windows users:

1. Click Share.
2. Choose permissions and then select Apply.
3. Add people.
4. Enter a message, if preferred.
5. Press Send.

For MacOS users:

There are only three steps to share a workbook:

1. Upload the workbook – With a web browser, upload/create a new workbook on OneDrive, OneDrive for Business, or a SharePoint Online library.

2.   Share it 

• If you uploaded the file, select the filename to access it. The workbook will appear in a new tab in your web browser.
• Select the Edit in Excel button. Click Edit Browser, if this button isn’t visible. Next, press Edit in Excel once the page has reloaded.
• Press Open Microsoft Excel.
• Once the file loads in the Excel programme, you might notice a yellow bar which states that the file is currently in Protected View. Select the Enable Editing option if that’s applicable to you.
• Press Share in the upper-right.
• Select Invite People. Then enter each e-mail address, and divide each with a semicolon. Ensure you also click Can Edit. When you’re finished, press Share.

Note: If you decide to send the link yourself, select Share in the upper-right corner, and then press Copy Link > View and Edit.

• If you selected the Share button in the last step, e-mails will be distributed to each    individual, listing your e-mail address. You’ll also get a copy of the message to see a preview.

3. Other people can access it

If you pressed the Share option, the recipients will get an e-mail message inviting them to access the file. They can select the link to open the workbook. A web browser will open, leading to the workbook to open in Excel for the Web. If they want to make any changes in the browser, they can select Edit Workbook > Edit in Excel.

Hint: If they’re working on the most recent version of Excel 2016 for Office 365 subscribers, they can enter the file directly via the Excel app. They can select File > Open.. > Shared, and then choose a file that has been shared by someone else.

Several people can update a workbook simultaneously which is known as co-authoring. Although, everyone must have a version of the Excel app that offers co-authoring. Currently, Excel for Android, Excel for iOS, Excel Mobile, and Excel 2016 for Office 365 subscribers are the versions that facilitate co-authoring. Without an assisted version, they can select Edit Workbook > Edit in Browser to alter the file in Excel for the Web.