Short answer
Most plumbers missing from Google Maps have one of seven problems: an unfinished profile, only one category, service areas left blank, an address set up wrong, thin reviews, hours that do not match reality, or they are simply too far from the person searching. Six of the seven are free to fix.
This is the most common question I get from plumbers, and the answer is almost never the one people expect. It is rarely a penalty and rarely anything sinister. It is usually a profile that was set up in twenty minutes years ago and never finished.
First, are you actually missing?
Before anything else, check properly. Searching your own business name while signed into your own Google account tells you almost nothing, because Google knows who you are and where you are standing.
Open a private window, or better, ask somebody in a different suburb to search plumber near me and tell you what they see. Your own view of the map is the least reliable one there is.
The seven reasons
1. The profile is unfinished. This is most of them. Categories, services, photos, description, hours. Google has less to work with than your competitor does, so it shows your competitor.
2. Only one category. Primary category set to Plumber and nothing else. Secondary categories like drainage service, gasfitter and hot water system supplier each open you to searches you are currently invisible for. Pick honestly, because categories you do not really service earn you the wrong calls.
3. Service areas left as one suburb. If you cover nine and the profile says one, Google has no reason to show you in the other eight. Five minute fix.
4. The address is set up wrong. Working from home is fine and very common. Hiding the address is correct for a service area business. But a hidden address configured badly can stop you appearing entirely, and you would never know.
5. Thin or stale reviews. Volume and recency both feed the map. A profile that stopped collecting reviews two years ago looks abandoned next to one with three from last month.
6. Hours that do not match how you work. If you take after hours calls and the profile says you close at five, you are being filtered out of exactly the searches worth the most money.
7. You are genuinely too far away. Proximity is a real ranking factor. A plumber based in one suburb will struggle to appear on a map for somebody standing forty minutes away, and no amount of work changes that. What does work is ranking in the ordinary results below the map, where distance matters far less.
Which of these is mine?
Work down the list in order. Six of the seven cost nothing but time, and you can get through them in an afternoon. If you have done all six and still nothing, it is almost certainly number seven, and the answer is a page on your website about the work you do in that area rather than more profile fiddling.
The bit most people miss
Profiles also get edited by strangers. Google lets the public suggest changes to your hours, your address, even mark you permanently closed, and it does not always ask you first. Somebody needs to be watching for that.
If you want a second pair of eyes on yours, that check is free and you keep the findings either way.