Microsoft To Do cannot sync: how to get your tasks syncing again
If Microsoft To Do isn’t syncing, the problem is usually one of three things: Microsoft’s service is having a hiccup, you’re signed into different accounts on different devices, or one app is stuck with bad cache, offline mode, or sync restrictions. Start by checking that you’re using the same Microsoft account everywhere, then force a refresh and sign out and back in on the device that’s behind. If one device still disagrees after that, the issue is usually local to that device.
Before you start
This applies to Microsoft To Do on Windows, iPhone, Android, and the web app. The fixes below don’t require Administrator or sudo privileges.
You may need to sign out and back in, and some steps can refresh or replace local app data on one device. Before you do anything more drastic, check the web app and one other device first so you know whether the tasks still exist in your Microsoft account.
Safe first checks:
- Open Microsoft To Do on the web and compare it with the device that looks wrong.
- Confirm the account name shown in the app on each device.
- Look for obvious offline mode, poor network access, or battery-saving restrictions on the problem device.
Symptom
Tasks show up on one device but not another, or changes you make on one device never appear elsewhere.This usually shows up after you add, edit, or complete a task on one device and the change does not appear on your other phone, your Windows app, or the web app.
Is Microsoft To Do down, or is it just your device?
Start by separating a service problem from a local sync problem. The easiest test is to open Microsoft To Do on another device or in the web app and see whether the same tasks appear there.
If the web app and at least one device all show the same tasks, Microsoft’s service is probably fine and the problem is local to the device that is out of date. If nothing matches anywhere, or changes you make on one device never appear anywhere else, the issue is more likely with the account or the service layer behind sync.
For a quick check, look for these signs:
- The web app shows your tasks, but one phone does not.
- One device updates, but another stays frozen on older data.
- You can add tasks on one device, but they never appear elsewhere.
- You seem to be signed into the right app, but the list still looks stale.
If the web app is also wrong, pause on device-specific fixes for a moment and make sure you are signed in with the correct Microsoft account everywhere. A surprising number of sync problems turn out to be two different accounts that look similar at a glance.
Why Microsoft To Do stops syncing on one phone but not another
This is usually a device-specific problem, not a broken account. One phone may be offline, signed into a different Microsoft account, or blocking background sync, while another device keeps working normally.
Common causes include:
- Different Microsoft accounts on different devices, especially if one is a work or school account and the other is personal.
- The app being stuck in offline mode or unable to reach the network.
- Battery saving or background app restrictions stopping refreshes.
- An outdated app version on one device.
- A damaged cache or local app data that no longer matches the server.
This also happens when the app is open on one device but hasn’t been refreshed recently. To Do can look fine at first glance while still holding an older copy of your lists.
If syncing works on the web but not on one phone, the phone is the place to focus. If it works on one phone but not the other, compare the account name shown in the app, then check network access and app permissions on the problem device first.
The fixes that solve most sync problems
Begin with the safest checks first. These fixes are reversible and often solve the problem without anything more drastic.
- Confirm you’re using the same Microsoft account on every device.
Open Microsoft To Do on each device and compare the signed-in account carefully. A personal Outlook.com account, a work account, and a school account can all look similar, but they do not share the same task data.
If the accounts do not match, sign out of the wrong one and sign in with the account that owns the tasks. If that does not change anything, the problem is not just a simple account mix-up.
- Force a refresh.
On the problem device, switch to another list and then back again, or close the app completely and reopen it. On the web version, refresh the page. This forces the app to ask for the latest data again.
If the list updates after a refresh, the app was just holding stale data. If nothing changes, move on to the sign-in check.
- Sign out and sign back in.
If the app still shows old tasks, sign out of Microsoft To Do on the affected device, then sign back in with the same account.
If you use the app for work or school, make sure you know which account is supposed to own the tasks before signing out.
If the tasks appear after signing in again, the local session was stuck. If they still do not appear, the issue is probably device-specific.
- Update the app.
Install the latest Microsoft To Do version on the device that won’t sync. Older app builds can get stuck or miss changes until they’re updated.
If the app was out of date and starts syncing after the update, that was the cause. If the app is already current, keep going.
- Check network access and offline behavior.
Make sure the device is online and not on a restricted connection. Also check that the app is allowed to use the network in the background, especially on mobile.
If syncing only works when the app is open, background limits are likely blocking it. If the app still refuses to update, the next issue is usually cache or device settings rather than the network itself.
What to check if your tasks still don’t match
If the basic fixes didn’t work, move on to the device-specific checks that most often block sync.
On Android, clear the app cache if the app is still showing stale data after sign-out and sign-in. Cached data can get out of step with the server and keep showing an old copy of your lists. If the cache is badly stuck, reinstalling the app can help, but use that only after you’ve confirmed the web app still has the tasks you expect.
On iPhone, check whether the app has permission to use cellular data and whether Low Power Mode or other background limits are affecting refresh. If the app can only sync when you open it, background limits are a likely cause.
On Windows, make sure the app is updated and that you’re not accidentally viewing a local copy after a sign-in problem. If the app keeps refusing to update, sign out, close it completely, reopen it, and sign back in.
On the web app, test in a private or incognito window. If the web version works there but not in your normal browser profile, browser cache or extensions may be interfering.
Here’s how to tell whether the data is really missing or just not appearing on one device:
- If the web app shows the task, the data still exists and the problem is local.
- If no device shows the task, it may never have synced or it may have been created under a different account.
- If only one list is missing, compare that list’s account and device history before changing anything else.
After you make a change, verify it by creating a small test task with a unique name such as sync test 1. Then check whether that task appears on the other device and in the web app. If the test task syncs but older tasks do not, the issue is more likely with the missing items themselves than with current sync.
Conclusion
If your test task appears everywhere, sync is working again and the remaining issue is probably an older local copy or a list tied to a different account. If the test task still doesn’t move between devices, focus on the one device that never updates and compare the signed-in account, app version, and network restrictions there.
Frequently Asked Questions
How do I know if Microsoft To Do is using the right account?
Open the app on each device and compare the exact account name shown in settings or profile. If one device is using a work or school account and another is using a personal Microsoft account, they will not share tasks.
Why do my tasks show on the web but not on my phone?
That usually means the service is fine and the phone is stuck locally. Sign out and back in on the phone, then check network access, background permissions, and app updates.
Will reinstalling Microsoft To Do delete my tasks?
Usually not, as long as the tasks are stored in your Microsoft account and you sign back in afterward. Before you reinstall, check the web app so you know the data is still present in the account.