You've seen the Google local services ads before, they have the Google Guarantee label on them. But when the Google Assistant started showing ads, people asked how does one not pay to show up in the local listings if you need the guarantee label but those come from local services ads.
These labels:
To be clear, we knew Google can show these if you are listing in by HomeAdvisor and Porch. But Greg Sterling dug into this and reported on How to appear in local services listings in Google Assistant and Google Home.
In short, if you do not have a listing with HomeAdvisor or Porch and you aren't in Google local services ads, you can submit a request to be Google Guaranteed using this form. Greg said "in order to be Google Guaranteed, businesses must pass a background check and have their license and insurance details verified." Now, those that pay get this pretty quick, but I am not sure how long it takes for those who fill out that form. In fact, Greg, nor did I, ever hear of this form before.
This form is specifically for local services providers in the businesses of Appliance repair, Electrical, Garage door repair, Heating and air conditioning, House cleaning, House painting, Locksmithing and Plumbing.
So no - you don't technically need to pay to show up as a local service provider in the Google Assistant or Google Home - you can fill out that mysterious form.
Forum discussion at Twitter.