Plumbing searches split cleanly in two. The first is the emergency: a burst flexi hose, a blocked toilet with guests on the way, no hot water on a winter morning. That person is on a phone, often standing in water, and types something short like "emergency plumber" with their suburb or "near me". They call the first plumber who looks real and looks local, and they rarely read past the first screen.
The second is planned work: replacing a hot water system before it fails, a leaking shower, gas fitting for a new cooktop, a drain that has been slow for months. These customers compare. They open three or four sites, check you do that particular job, look for a licence number and some sign you've done it before, and often ask two plumbers to quote.
Both groups decide on trust signals they can see quickly: a licence number, a business name that matches the van, real photos instead of stock images of someone in a hard hat, recent reviews, and the suburbs you actually cover. A plumber who lists "all of Sydney" is less believable than one who names the areas they can reach quickly.
How you charge matters too. Customers want to know whether there's a call-out fee and how pricing works before they ring, even if you never publish a number. A sentence explaining how you quote, whether that's a fixed price after inspection or a call-out followed by time and materials, saves a lot of awkward first calls.