The easiest ways to sign into two Office 365 accounts at the same time

Office 365 is frequently used by businesses. However, with more and more people working from home, the need to manage both your business and personal account at the same time is increasing. In response to this, many people like to sign in to and quickly switch between both their accounts. Albeit, not everyone already knows how to do this. That’s where we come in. 


  1. Open O365 online 
  2. Sign in to your first account 
  3. Open a private/incognito window 
  4. Sign in to your second account 
  5. Sign in to the second account with your new window 

In this post we’ll be exploring the method used to simultaneously sign into two accounts, some drawbacks to using this method and how you can access incognito mode to attempt the method. 

Quick links: 

Accessing incognito/private mode in your browser to sign into two Office 365 accounts at the same time

Fastest method 

Below listed are some frequently used browsers, Chrome and Firefox in particular. We’ve left the shortcuts to get in to incognito/private mode quickly listed here. If you plan on using this often, we recommend trying to remember the shortcut that applies to you.  

Browser Used in walk through Shortcut 
Microsoft Edge No Ctrl+Shift+N 
Chrome No Ctrl+Shift+N 
Firefox Yes Ctrl+Shift+P 

Signing into two Office 365 accounts via incognito mode 

Please note, we will be using Firefox for this walk through. Despite this, you should be able to follow along just fine- provided you’re able to access your browser’s incognito/private browsing mode. 

Step 1 – Open both windows 

  • While you can simply repeat the steps for one window after first completing all steps for the first, we’d like to save time by doing both at once. In the following images, please expect the normal window to always be on the left, and the private window to always be on the right. 

Step 2 – Sign in via Office 365 login page 

  • After first visiting the stated page: Select login and enter your credentials for one account into the normal window. Then repeat for your second account in the private window. You’ll be met by the home screen on both windows. 

Drawbacks to using incognito mode 

Being flagged 

While uncommon, some sites may flag your for “suspicious activity” when you access their services via a private window. While this doesn’t usually mean anything significant, you may be required to complete a form of human verification- such as a Captcha. 

No caching 

When using private mode on most browsers, no history or cached data remains on the device after closing the window. This means that you’ll have to sign into service every time you’re using a new private window. An additional downside this causes is slower site loading. Without caching site data, website content will have to be downloaded/re-downloaded and displayed from new each time you access a site. 

No history 

Because private mode blocks history logging, you will no longer have an accessible list of recently visited sites. This can be problematic if you were researching a topic or studying, or wished to quickly re-access some closed work. Primarily because you would have to manually re-find the service and re-enter form data (due to the lack of normal caching) such as login credentials. Albeit, this drawback can be compensated for via the use of site bookmarks, which with some browsers (such as Mozilla Firefox) are accessible in private windows as well as your standard browsing windows/ 

End note 


By now, we’ve learnt to access incognito/private mode within browsers like Microsoft Edge, Google Chrome and Mozilla Firefox. How we take advantage of private browsing to simultaneously utilise two Office 365 accounts. We’ve additionally also explored the drawbacks that come with exploiting private browsing- as a result of the limited caching that comes with private browsing, lack of history logging and potential for flagging. 


As usual, this section is dedicated to thanking readers for their support. We’d be pleased to know you found this post useful and/or informative. If you have any more Office 365 related queries, please consult our related articles (listed below). However, if you have other queries, consider looking at the rest of the site. We’re frequently posting new stuff each week and may just have the guide or troubleshooting tips you need. Regardless, we wish you a good day/night. Farewell readers. 

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Jack Mitchell

Jack Mitchell has been the Operations manager at telecoms and MSP Optionbox for more than 4 years. He has played a crucial role in the company, from marketing to helpdesk, and ensures that the IT requirements of over 300 clients are continuously met. With his innate passion for technology and troubleshooting and a particular interest in Apple products, Jack now delivers the most comprehensive tech guides to make your life easier. You can connect with Jack on LinkedIn.

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