What can I do if my Mac reminders won't sync to iPhone?

WORKED!! I just updated my MacBook Air Early 2015 to Monterey 12.7.4 and iPhone 15Pro to IOS 17.4.1. I also turned off Reminders in iCloud on my MacBook only and back on and everything now syncs. It took a few minutes because I was going to reply that it didn't work but it ended up working. I've tried several test; adding reminders on my MacBook and then when they appear on my iPhone, deleting them and also resorting the different reminders list and everything seems to be syncing up fine now. Thanks for the suggestions from others!

Resolved it on my end:

Turns out I had "Reminders" under my fastmail account, and same title "Reminders" on iCloud.

Reminders list was created on my computer, but there is no option on the phone for that.

Solution was to remove the "Reminders" list from laptop and keep only one from iCloud. Once i had that done, everything syncs between lists.

The confusion is that in desktop app it looks like a single list, "reminders" fastmail and "reminders" iCloud are in one happy "Scheduled" list. So on desktop I see them all, and on phone - only those that belong to iCloud

TLDR;

Don't use other than iCloud accounts for reminders

Apple locks user on their infra :shrug:

Actually I was just able to fix this. From everything I was reading it seemed that some sort of corrupted reminder was likely causing the issue so I went into my desktop reminders app and deleted a bunch of lists and reminders, including a few daily recurring ones. Suddenly it started syncing!

I suggest going in and cleaning house on your Reminders to see if you can delete the culprit.

I had the same problem as many of you: reminders created on my MacBook weren't syncing with my phone app, and none of the suggested solutions online were helpful. Then I realized that my iCloud storage was full! As soon as I deleted some unnecessary files to free up space, it synced within a couple of minutes.

For those who still have this problem, I highly suggest having at least 2GB of free space on your iCloud for smooth syncing between devices. Thanks 🙂

Resolution: In reminders there are "lists" that have to be synced across all of your devices in order to be properly associated with the reminders in iCloud. I recommend creating a list under the "iCloud" option in reminders and moving all of your reminders there. it's simple.. more customizable than lists NOT in iCloud and immediately syncs to all devices signed into the same Apple ID

Hi, what I did was clear the completed reminders and it started syncing;

I think it was the fact that some of the older reminders were started and completed under older versions of iOS, on devices I owned years ago (have been using iPhones for the past 12 years);

definitely recommend clearing your completed reminders if all else fails!

I had the same issue, and what I realized is that my iCloud storage was full, so that's why it wasn't syncing. I deleted some stuff and after a few minutes my Reminders app started syncing back again.

Having the same problem sync'ing Exchange-based list reminders (Microsoft 365 or "To Do") between the REMINDERS apps on my iPhone and MacBook Air M3. Have followed all the guidance in the support docs, as well.

Adds to this thread:

• I monitored the Microsoft cloud "authoritative" store while reproducing various reminder tasks (create, delete, update) and it seems to me that iPhone to Microsoft 365 is working well. The problem is Mac to M365.
• I ran across an old article that suggested REFRESHING CALENDARS also refreshes the reminders. This seemed to do the trick for me! Open the Calendars app on macOS and under the VIEW menu choose REFRESH. This would support a perception that the sync code itself works but it just isn't getting triggered correctly by the Reminders app.

I will do some additional testing and update this post if I learn more.

I HAD SAME ISSUE AND DISCOVERED IT WAS BECAUSE WHEN I SET A NEW REMINDER ON MY IPHONE, THE DEFAULT LIST ON MY PHONE SETTINGS WAS 'LOCAL' REMINDERS RATHER THAN AN 'ICLOUD' REMINDERS LIST. HOPE THAT HELPS?

Hey Willssr,

If your Reminders don't sync as expected, the following steps may help.

"Things to check first

1. Check the system status of iCloud Contacts, Calendars, or Reminders for services outages or connection issues.
2. If a reminder isn't showing up on some of your devices, make sure that your iPhone and iPad have the latest version of iOS or iPadOS, or that your Mac has the latest version of macOS.
3. Make sure that you're signed in to iCloud with the same Apple ID on all of your devices. Then, check that you turned on Contacts, Calendars, and Reminders in your iCloud settings.
4. Check that the date and time settings on your device are correct for your current location. " If your iCloud Contacts, Calendars, or Reminders won’t sync

Be sure to click the link for additional troubleshooting steps. We hope this helps!

Sincerely.

I noticed my desktop and iphone were out of sync, so I started playing around to see if I could figure it out.

Running into several annoying discrepancies between multiple devices, where a Reminders entry will be on 1 device, and not others.

Testing I was across: iPhone 16, an M4 iPad Pro, and a new M4 Pro mac mini, and for giggles, logged into the web version of reminders.icloud.com. All running the latest version of reminders.

The Lists metadata appear to sync correctly - the name, icon, whether it's an auto-list, etc. are synced across all the devices correctly. However the counts on each list are off by several reminders. For example: "Completed" on ipad was 1248, desktop was 1094, and iphone was 707; the web app doesn't show completed. My primary list was 14 on ipad, 13 on Desktop, and 16 on iphone, and 14 on the web.

I've spent the last 40 mins testing every permutation of adding, updating, moving, completing, and deleting reminders across all devices. The majority of the time, adding a reminder or updating a reminder syncs quickly across all devices. However, marking complete or deleting reminders results in discrepancies across various devices, and I can't see any rhyme or reason. Every once in a while, a reminder created on 1 device never shows up anywhere else. No matter how long I wait or if I restart the app / reboot.

I'll complete a reminder on 1 device, and one device won't ever update, even if I close the app, reboot the device, re-sync icloud, etc. And it's never the same device.

Another fun encounter. Every once in a while I noticed a new reminder created on one device would only be displayed partially on another device. For example, after 30 minutes of testing, I created a reminder "I AM ANGRY" and it synced as "I AM A" on one device, and was fine on another, and never showed up in the web version. It happened again about 5 minutes later with a different new reminder I created - the title was only partially captured.

I am pretty sure it's some crummy syncing code, likely exacerbated by a situation someone else here noted where reminders created, updated, and/or scheduled under older versions somehow doesn't sync properly.

Yes, I've taken all the recommended steps:

• rebooted devices
• signed-out / signed-in to iCloud (yes, they're all the same account)
• confirmed the primary list is set properly in all devices, and is in iCloud

I've gone ahead and clear out ALL my completed, deleted, etc. on all devices to clear out the cruft of legacy created reminders as much as possible, but the problem still persists. Sometimes a device either doesn't receive or send out an update.

Apple Support has not followed up; when I ping the support thread I hear nothing back.

iCloud syncing for Notes, Calendar, Files, Home, Wallet and so forth are syncing just fine, but Reminders is completely broken.

After talking to some former Apple engineers, it seems very clear there is some engineering fix to reset the app service in the background for my iCloud account, but actually getting that done or approved seems impossible without having a personal contact inside the company. Very frustrating.

I've decided to move on to using Things instead.

Good afternoon Willssr,

If you would like to speak with an Apple advisor about the issues you are having with Reminders on your Mac, click the link below:

Get Support

Or open this article and call the phone number for your region (or the closest one to it) when you have the time.

Contact Apple for support and service - Apple Support

Take care.

Another 40 minutes of testing (why do I do this to myself?!).

iCloud storage has gobs to spare, so it's not an issue with storage.

I have discovered that more often than not (but not always!) actions taken on my iphone 16 don't cascade to the other devices. Ever.

Creating. Completing. Updating. Moving. Deleting. A significant % of the time (greater than 50% in the last round of testing), the update never reaches the cloud.

I've tested on a variety of network connections, and nothing seems to resolve this discrepancy.

<sigh>

With reminders being so unreliable, it's time to switch to something else. I guess I can go back to Things 3, or something.

Same problem here. Reminders syncs across all devices and the iCloud web app, but not desktop. Desktop gets the latest but can't push any changes you make on it. Problem just showed up one day and never went away. I was hoping installing the latest OS (Sonoma) would fix it but no such luck. It's been over a year now...