I finally figured out how to delete competed reminders on iOS.
You can create a shortcut to do this task. It took me a while to figure it out. In Shortcuts, you have to select what you want to act upon, and then act upon it in another step.
First, when you create a shortcut, you add an action. Go to Apps, look for Reminders, and then select Find Reminders. You add a filter in that step. One of the things that confused me is when I clicked on the filter, it showed me only List is and the name of a list. It took me a while to realize you can click on List is to change the filter. Change the filter to Is completed.
Now add a second step. If you need to, Select Apps and Reminders again. Now select Remove Reminders.
That’s it. Selecting this shortcut will remove deleted reminders. I had over 15,000 completed reminders and it took about ten minutes to run. If you leave Shortcuts before it finishes, the reminders don’t delete. After the first delete, it now runs in under a minute.
You can add an automation and have it run on a regular basis.
I use the Reminders app as a ‘to do’ list and so have perhaps 50 specific reminders.
co-op shopping list, grocery shopping list, recipes, movies and so on.
I find that if I click to the right of the list of completed items and then shift click at the end, I can delete by pressing my delete key. Be careful. The completed list displays with the leading button selected but your uncompleted items are included beneath that. If you select it all you will have to consult the back up in your hairy computer.
I find that if I click to the right of the list of completed items and then shift click at the end, I can delete by pressing my delete key.
That’s what I had been doing, but that means going to my Mac to do something I usually use my iPhone for.
It’s like groups in Contacts. You can use groups on the iPhone in various places, but you can’t put contacts into groups on the iPhone. You need a Mac to do that. And, although the iPhone can display a contact correctly if you check it’s a company contact, you can’t set a contact to be a company.
@jps Instead of using Reminders.app for a list, try the Notes.app and use the Checklist function.
On iOS (and maybe Catalina) the ticked items can go to the bottom of the list (as a preference). Plus it can be shared with another AppleID user.
Once ticked (when job/item is completed), the listed items can be unticked, ready for next use (no need to re-type the items).
For a fully featured app (requires annual subscription) have a look at AnyList.