I have a Family plan and in order to invite family, you must add an address. I put in multiple addresses and still nothing. It's 2019 and Spotify still has no Customer service line. If anyone knows what to do to fix this it will be very appreciated as i've seen a bunch of people with the same problem.
We are aware of an issue where the address can't be found when trying to sign up for Family Premium and are currently investigating this.
Feel free to contribute in this topic where we gather information from affected users and keep everybody up-to-date. Be sure to comment or subscribe in the topic to get notifications. We'll get this sorted as soon as possible.
Sorry for the inconvenience. Let us know if you have further questions.