Unable to Block Calls on iPhone with new Tahoe O/S-Won't Retain Block Contact Setting

I was also told by Apple that the limit was 20K a while back. I was at 17,000 so also figured I was good to go, but since 26.5 I was unable to block calls. I read something on a post about this same issue where a guy said that Apple lowered the number of contacts allowed to 3,000. Since I don't have faith in Apple fixing anything soon I figured maybe this guy knew what he was talking about. So I started deleting blocked contacts. With the number I had, plus they can only be deleted one at a time, this took me some time. Once I got below 3,000 I tried blocking a contact again and it worked! So, since in iOS 26 apple starting listing blocked contacts by phone number rather than chronologically as was done earlier, I decided to delete all of them to give me more room. This has been over a week and it still working as intended. Give it a try, YMMV

blocked not working solutions 

Solution 1: 

Reduce the number of blocked to under 3000. To view and manage your blocked contacts, go to Settings > Privacy & Security > Blocked Contacts. It will show how many you have blocked. Then click the blocked numbers and then edit and delete one at a time. This is way too time consuming for me.

Solution 2:

simply add numbers you want to block to any previous contact you have blocked earlier. You can add max 500 numbers per blocked contact. So as long as you have at least a few earlier blocked contacts, this should work.

Issue: In case of an unknown number ! you want to block and could not be added to the blocked contact. Add a name to the unknown number ("added a name"; NOT "added the number as a contact”) and then add it to a previously blocked contact.

Solution 3: On a Mac open mail preferences then clicked Junk then click Blocked then click the top blocked item hold shift key and click the bottom one so they are all highlighted then click the minus button at bottom, it will spin and spin but eventually delete them all. That worked for me. 

Solution 4: But if you don’t have a Mac computer, the iPhone Settings -> General->Transfer or Reset iPhone -> Reset->Reset all settings will erase blocked messages but also does this:

What this action removes:

    •    Network Settings: Saved Wi-Fi passwords and paired Bluetooth devices are forgotten. 

    •    Apple Pay: All payment cards added to Apple Wallet are removed. 

    •    Keyboard & Display: Custom keyboard dictionaries are cleared, and features like dark mode, display zoom, or custom brightness revert to factory defaults. 

    •    Privacy & Location: Any permissions you previously granted to apps to access your location or photos will be reset, forcing apps to ask for permission again.

FYI, iPhones do not run Tahoe.

Tahoe is the name of macOS 26. Although Apple is now using model-year-based numbering for all of their related operating systems (macOS, iOS, iPadOS, watchOS, tvOS, visionOS), only macOS has a name as well as a number.

If your carrier supports it, you may want to set your iPhone to filter spam calls. ("Calls identified by your carrier as potential spam or fraud are silenced, sent to voicemail, and moved to the Spam list.")

Screen and block calls on iPhone - Apple Support

Some have been reporting the same issue. You can submit a bug report to Apple.

Feedback - iPhone - Apple

How many blocked contacts do you currently have in your list?

sharifromdelraybeach wrote:

I have only 3000 blocked calls/emails and the Apple Store said the limit is 20,000 --- so I am well within the limit of blocked calls & emails (It's all in one folder).

As far as I know, the "20,000" isn't listed anywhere in user documentation. It sounds to me like an arbitrary limit imposed for performance reasons. Whatever the limit is, the phone has to maintain a structure that is potentially that large, and check it every time a call comes in.

Someone could have decided that the old limit was higher than needed, and lowered it.

sharifromdelraybeack, I am glad it worked for you. While I am upset that they reduced the limit by 17k with the intro of iOS 26, I wish they would have told us. Funny thing is that since that time I have been on the phone with Apple support, and their tech's didn't know about it. I also wish they would have left the sorting of the blocked contacts as chronological rather than changing the sort to by phone number. That way we could easily just delete the oldest blocks.

And just so you know, blocking numbers does absolutely nothing to stop scam or telemarketing calls. These people use different numbers for every call. Those calls will just keep coming.

Wondering which app is best for blocking spam calls