Custom label in contacts

Open contacts app

Choose and open a contact

Tap on Edit (top-right)

Tap on add a phone number

Tap on the proposed label

Scroll down and tap on Add Custom Label

Type the new label

Tap Done.

Regards

Giulio

I have the same issue and it's driving me crazy! I have 2 phones..my work phone is a 6 and my personal phone is an X. Both have the latest OS versions installed. My 6 has the choice for a custom label and the X does not. Both phones have the same default account under Contacts so that can't be the issue (I saw that as a solution in an earlier post). Even if you share a contact with a custom label it does not come over that way. There is not a choice for a custom label at all anymore. I changed from a 6 to an X for my personal phone last summer and that's when the issue started. The only choices are what is below.

I checked mine and it looks nothing like yours. Are you running 12.1.4?