Queensland's painting licence rules don't change with latitude. The QBCC licenses painting work valued at more than $3,300, and its advertising rules, which cover websites, ask for your licensed name, licence number and a statement that you're licensed under the QBCC Act. Our Brisbane painters page explains them, along with the QBCC's figures on defective paintwork. The rest of this section is about Townsville itself.
The Bureau of Meteorology's averages for Townsville Aero show why most of the Townsville year suits exterior painting. It averages 8.5 hours of sunshine a day, more than nine from August to November, and about 121 clear days a year. Rainfall comes to about 1,165 mm, but on only about 65 days, and around 34 of those fall from January to March; from July to September there are two or fewer rain days a month. That's a long dry window for outside work, and plenty of sun on the walls that cop it.
Council's City Plan includes a Character residential zone covering parts of the older suburbs, and council publishes a fact sheet on what it covers and which work needs approval. We'd link to that fact sheet rather than summarise it on your site: whether a particular job needs approval is for the owner to confirm with council. What your site can do is ask, on the quote form, whether the house is in a character area and whether the roof colour or material is changing, so the question comes up before the job is booked, not after.
Places on the Queensland Heritage Register follow state rules, as they do anywhere in Queensland: the state's General Exemption Certificate covers repainting in the existing colour scheme under set conditions, and work outside those conditions needs the state's approval. Bodies corporate are a smaller share of the work than in Cairns: a Titles Queensland count last updated in February 2022 put 1,534 community titles schemes in Townsville, against 1,865 in Cairns.
Magnetic Island is part of the city. SeaLink runs passenger ferries from the Breakwater terminal, and Magnetic Island Ferries runs the island's only vehicle ferry, from Ross Street in South Townsville to Nelly Bay, a crossing of about 40 minutes with vehicle bookings essential, which is how a painter's ute and ladders get over. We're an Adelaide team at Hutt St and work with Townsville businesses by phone and email: you send photos, licence details and the suburbs you cover, and we send a draft link to check between jobs.