365 Apps set to US locale

[Sheridan]

This seems to be a recent thing, or its just being noticed more recently but whenever users are in Word/Excel in 365 the region is US even though our PCs, Edge, Chrome etc and tenancy are all set to UK but it insists we're US

 

Is there no way to force the locale across 365 apps, as its a total pain with dates etc?

Edited September 17, 2025 by Sheridan

[ZeroHour]

I thought you might have been able to set it via: Cloud Policy service - Microsoft 365 Apps admin center - Microsoft 365 Apps admin center but it wont load the policies for me to take a look, the same thing happens in the InTune version of those settings.

[Sheridan]

Its odd, as our domain PCs are UK in everything - and Edge has a policy show use Uk. When I check the users mailbox with 'Get-MailboxRegionalConfiguration -Identity' and it shows the correct en-GB region and date/time formats!

 

Yet when in Excel 365 it defaults to English US so the date fields are wrong, which is causing issues with users creating files on site (saved on one drive) and then opening them either on or off site in the web app as the dates are all wrong for us!

[Rob_D]

Have you checked/tried changing the default site collection settings here: https://<site url>/_layouts/15/regionalsetng.aspx ?

[psydii]

I was looking at configuring a new Microsoft 365 Apps deployment in InTune the other day and the only options for English  were "none" (install as per OS) and Engligh (US).  This seems like it might be a problem. But then again deploying the US/Int version of Windows brings its own problems with timezeone defaults sticking... so maybe its a "you should have installed localised version of Windows" problem. I parked it as a "look at it again when you have more time" job since the current deployment method (SCCM) of an ancient build is still working fine.

 

[psydii]

2 minutes ago, Rob_D said:

Have you checked/tried changing the default site collection settings here: https://<site url>/_layouts/15/regionalsetng.aspx ?

Oh. Now there is another thing in my "...when you have more time" pile.

[ZeroHour]

The policies page finally loaded but I am not sure if this 365 Office Policy would work:

 

 

I am not sure if this would be needed as well if its not the UK version of Office 365 installed:

 

[Sheridan]

18 minutes ago, ZeroHour said:

The policies page finally loaded but I am not sure if this 365 Office Policy would work:

 

 

I am not sure if this would be needed as well if its not the UK version of Office 365 installed:

 

Interesting - there was no policy set for this so I thought I'd create one

 

However that failed with an obscure error: 

Couldn't retrieve data for 'OfficeSettingsContainer'. Use '<guid>' to report this issue to Microsoft.

 

 

 

[ZeroHour]

2 minutes ago, Sheridan said:

However that failed with an obscure error: 

Couldn't retrieve data for 'OfficeSettingsContainer'. Use '<guid>' to report this issue to Microsoft.

Retry and it might go through. That whole part of office 365 seems to be having issues right now as that happened to me then worked a couple of minutes later. Yesterday I couldn’t even get the policies page to load.

 

i don’t know how long it takes for policy changes to roll out though, knowing o365 it will probably be a day anyway for clients to pick up the change and also if it’s having problems editing the policy clients might get errors pulling the policies.

[Sheridan]

1 minute ago, ZeroHour said:

Retry and it might go through. That whole part of office 365 seems to be having issues right now as that happened to me then worked a couple of minutes later.

i don’t know how long it takes for policy changes to roll out though, knowing o365 it will probably be a day anyway for clients to pick up the change.

Yeah the fact the policy page takes forever to loads isn't a good sign!

[ZeroHour]

Let’s face it the policy sounds like it does exactly what you want but this wouldn’t be the first time where a policy doesn’t do what it says it does because it’s A) broken B) stealth depreciated C) does something completely different 🤣 

it should also exist in InTune and group policy (maybe)
 

Post back next week and let us know if it works/doesn’t work.

[Sheridan]

Finally managed to create the policy - just took a dozen attempts! I'll see if it makes any difference over the next few days/week

[Sheridan]

1 hour ago, Rob_D said:

Have you checked/tried changing the default site collection settings here: https://<site url>/_layouts/15/regionalsetng.aspx ?

All set to UK in there as well!

[Sheridan]

Policies didn't work and I did a bit of testing over the weekend - using a standard test account at home on Macos/Safari it still picks up the locale as US - so that's with no domain/network/GPO settings involved!

[CacheMeOutside]

4 hours ago, Sheridan said:

Policies didn't work and I did a bit of testing over the weekend - using a standard test account at home on Macos/Safari it still picks up the locale as US - so that's with no domain/network/GPO settings involved!

This has been on my list to take a deep dive on for some time, and was hoping your post would garner a simple fix from someone in the know. 

 

Everyone's favourite AI Chatbot came back with the following: 

 

Ahh yes — that one’s been catching a lot of people lately. You’re right: even if the Windows region, browser locale, and M365 tenant settings are all UK, Office on the web (Word/Excel/PowerPoint Online) often defaults back to US locale. It’s confusing because different parts of Microsoft 365 respect different locale settings.

Here’s the breakdown:

---

🔎 Why it happens

• Office apps (Word/Excel Online) don’t always use the tenant or site collection locale.
• They usually take the user’s personal M365 account language & regional settings.
• If those aren’t set, they fall back to en-US by default.

So you can set the PC, Edge, Chrome, even SharePoint site to UK — but the Office apps can still decide “nah, US” if the user profile hasn’t been overridden.

---

✅ Fixes / Things to Try

1. Change the user’s Microsoft 365 profile regional settings

1. Go to: https://myaccount.microsoft.com/settingsandprivacy
2. Select Language and region
3. Set:
   • Display language = English (United Kingdom)
   • Regional format = English (United Kingdom)
   • Time zone = London/Dublin

This directly influences Word/Excel/Outlook Web App regional defaults.

---

2. Outlook Web App regional settings (still used by some services)

1. Open Outlook Web
2. Gear ⚙ → View all Outlook settings
3. General → Language and time
4. Set to UK.

Even if Outlook works fine, this change still feeds into the Office web apps for some users.

---

3. SharePoint (site-level vs personal OneDrive)

You already checked the tenant’s site collection settings, which is good. But note:

• Each user’s OneDrive (personal SharePoint site) has its own locale too.
• URL format: https://<tenant>-my.sharepoint.com/_layouts/15/regionalsetng.aspx

Worth checking that for a test user.

---

4. Force via PowerShell (Org-wide defaults)

There’s no single tenant-wide switch sadly. But you can script updates to:

• Mailbox region settings (Set-MailboxRegionalConfiguration)
• SharePoint site defaults (Set-SPOSite -LocaleId 2057 for UK)

Example for a user mailbox:

Set-MailboxRegionalConfiguration -Identity [email protected] -Language en-GB -DateFormat "dd/MM/yyyy" -TimeFormat "HH:mm" -TimeZone "GMT Standard Time"

This makes sure calendar, dates, and times stick to UK formats.

---

⚠️ Reality Check

There’s no single “force UK for everyone” button (annoying, I know). It’s a combo of:

• Tenant defaults
• SharePoint defaults
• User profile language/region
• Mailbox regional config

If any of those are unset, Office apps often slip back into en-US.

---

👉 My recommendation:

• Set org defaults (which you’ve mostly done)
• Run a PowerShell script to bulk set mailbox regional settings for all users
• Educate staff to check/update their own My Account → Settings & Privacy → Language & Region

---

 

[Sheridan]

Yeah its a bit annoying that we set everything to UK from tenant downwards and MS just decided to switch to US and tell us we can change it ourselves! That's fine for individuals but its a pain for a school!

[NegativeKillDeath]

Its a policy that appears to be born out  of the business road warriors in the US who might want to change their own time zones depending on which of the 4 US zones they are currently in. 

[ZeroHour]

21 hours ago, Sheridan said:

using a standard test account at home on Macos/Safari it still picks up the locale as US

I dont know if all the policy stuff works on the Mac versions of office yet tbh. Lots of things like Edge policies didnt although I *think* edge might now.

[Olliedawg]

Did anyone find resolution to this?... It's causing a headache for our PowerBI dashboards when viewed in the web version.

 

All our web apps (in browser) are displaying US date formats, desktop apps are all in UK format.

 

We are using English International version of Windows

 

If i run

 

get-mailboxregionalconfiguration -identity [email protected]

 

It returns this

 

Identity             Language        DateFormat TimeFormat TimeZone
--------             --------        ---------- ---------- --------
Teacher Test         en-GB           yyyy-MM-dd h:mm tt    GMT Standard Time

 

 

I visited  https://<tenant>-my.sharepoint.com/_layouts/15/regionalsetng.aspx

 

Time zone & Region were set to US, I have manually changed these to UK, however no apparent difference yet.

 

 

[Sheridan]

I went back and forth on this with MS and their answer was basically that's the way it is, and the users have to change it themselves manually

[Olliedawg]

1 hour ago, Sheridan said:

I went back and forth on this with MS and their answer was basically that's the way it is, and the users have to change it themselves manually

 

[robintech]

Not sure but Set-MailboxCalendarConfiguration -WorkingHoursTimeZone  ‘GMT Standard Time’  seemed to fix some issues for us with Word online being the wrong language. Might be unrelated though

 

[Olliedawg]

7 minutes ago, robintech said:

Not sure but Set-MailboxCalendarConfiguration -WorkingHoursTimeZone  ‘GMT Standard Time’  seemed to fix some issues for us with Word online being the wrong language. Might be unrelated though

 

Ours are already set to GMT Standard Time.

 

Everything looks to be set to English UK/GMT. The only thing that isn't is the "regional settings" under "https://<tenant>-my.sharepoint.com/_layouts/15/regionalsetng.aspx", which is set to 

• Locale: English (United States)
• Timezone: UTC -8 Pacific Time (US and Canada)

I tried changing mine to English, and this did change dates in O365. I tried this with another user (our data person), and his still showed US format calendar dates within powerBI. Not sure what else to do in that scenario