Two permissions catch small businesses out constantly, both because they seem too small to need asking about: whether you may work from where you live, and whether you may put up a sign.
Trading from home
Property is zoned for a use — residential, business, industrial — and a home is generally zoned residential. Many home-based businesses operate without difficulty, because what municipalities care about is impact on the neighbourhood rather than the fact of work happening.
The questions that decide it are practical. Do customers come to you? Do staff? How many vehicles, how often? Are there deliveries by anything larger than a courier van? Is there noise, smell, or anything stored outside? Are you using a substantial part of the property, or a spare room?
A consultant with a laptop is a different proposition from a panel-beater, and municipalities treat them differently. Where consent is needed it is usually obtainable, sometimes with conditions attached about hours or parking, and the process involves notifying neighbours — which is worth thinking about before it becomes their first news of it.
The practical risk of not asking is a neighbour's complaint. That is what triggers most enforcement, and it arrives after you have built the business around the arrangement.
Signage
Almost all outdoor signage requires municipal approval, including things people do not think of as signs: a board on a wall, vehicle branding in some cases, a banner on a fence, an A-frame on the pavement.
What is assessed is size, position, illumination, and whether it obstructs or distracts — particularly near roads. Heritage areas and some suburbs have additional restrictions, and a landlord's permission is not the same as the municipality's.
Unapproved signage gets removal notices and fines, and the sign usually has to come down. Since a sign is a real cost to produce, asking first is cheaper than it sounds.
If you rent
Your lease and the zoning are separate matters, and both can stop you.
Read what the lease permits before signing: the permitted use clause may be narrower than the zoning, a sectional title scheme's rules may prohibit business use of a unit entirely, and body corporate conduct rules can restrict signage, hours, deliveries and customer access.
Confirm the zoning independently rather than relying on the landlord or the agent. They may be mistaken, and the consequence lands on you.
The order to do this in
Confirm the zoning permits your use. Then check the lease or the scheme rules. Then apply for signage. Then commit money.
Almost every expensive version of this problem is the same story in a different order: premises committed to first, permissions checked afterwards.
General guidance, not legal advice. Zoning, consent and signage rules are set locally and vary considerably; confirm with your own municipality before committing to premises.