There are a number of possible explanations for why verification codes don't always arrive. Read through the list of the most common causes, and see if any of them apply to you, or use our troubleshooter to help guide you.

SharePoint is a browser-based app that you connect to through your web browser, like so: Go to office.com, and sign in to your work or school account. In the upper left corner of the window, select the app launcher > All apps > SharePoint.

For technical support, go to Contact Microsoft Support, enter your problem and select Get Help. If you still need help, select Contact Support to be routed to the best support option. Learn how to manage your Microsoft account security info and troubleshoot verification code issues.

The Microsoft Authenticator app helps you sign into your accounts when you're using two-step verification.

Hotmail is now Outlook.com. Learn how to sign in to access your Outlook.com, Hotmail, Live, or MSN email account.

Troubleshooting verification code issues. Avoid and report Microsoft technical support scams. Learn how to unlock your Microsoft account and resolve 'account has been locked' error message.

Mobile device or work phone call: Enter your mobile device number and get a phone call for two-step verification or password reset. For step-by-step instructions about how to verify your identity with a phone number, see Set up security info to use phone calls.

The VLOOKUP and HLOOKUP functions, together with INDEX and MATCH,  are some of the most useful functions in Excel. Note: The Lookup Wizard feature is no longer available in Excel. Here's an example of how to use VLOOKUP. =VLOOKUP (B2,C2:E7,3,TRUE) In this example, B2 is the first argument —an element of data that the function needs to work.

Add, remove or update an email address or phone number. If you want to make changes to the email addresses or phone numbers associated with your Microsoft account, use our guided support tool below to help you update the right information in the right way.

To find a customer service phone number in your country, please click a region and find your country. Note: Support cases for Surface devices may only be initiated online.