A supplementary plate is the small rectangular sign mounted under a main sign. It adds a condition the main sign can't show on its own: when it applies, how far it applies, which vehicles it applies to, or why the warning is there. On private roads, car parks, estates, mines and construction sites, the right plate can turn a generic sign into a clear instruction.
On public roads, signs are installed by councils and state road authorities. This guide is for private property and work sites, or for contractors working under an approved traffic management plan.
1. When and where a rule applies
At all times ยท Next (x) m ยท Next (x) km ยท On bridge ยท To traffic from left
2. Exceptions
Use these under a no entry, no stopping or road closed sign when some vehicles still need access.
Authorised vehicles excepted ยท Buses excepted ยท Bicycles excepted ยท Emergency vehicles excepted (NSW) ยท Construction vehicles excepted (NSW) ยท Garage and loading dock access excepted (NSW) ยท Except in emergencies
3. Vehicle size and weight
Pair these with a no trucks or height clearance sign. See our height clearance signs guide.
Over (x) t GVM ยท Vehicles over (x) t GVM ยท Over (x) m high ยท Vehicles over (x) m high ยท Over (x) m long ยท Over (x) m wide
4. Warning sign plates
These sit under a yellow warning diamond to add detail.
Advisory speed (xx km/h) ยท Distance (x) m ยท Next (x) km ยท Next (x) m ยท When wet ยท When frosty ยท Boggy when wet ยท Curve tightens ยท On side road (arrow) ยท One lane ยท Added lane ยท Crossing ahead ยท Raised crossing ยท Trucks use low gear (NSW)
5. People to watch out for
School ยท Preschool ยท Playground ยท Aged ยท Blind ยท Disabled ยท Deaf children (NSW)
6. School pick-up and drop-off (NSW)
Kiss and ride area ยท Pick-up and set-down area ยท School drop-off and pick-up zone
See our school and childcare signs checklist for the rest of the school gate.
Matching the plate to the main sign
- Order the plate in the same material as the main sign so they age the same. Reflective aluminium is the usual choice for roads and car parks. See reflective vs non-reflective signs.
- Mount the plate directly under the main sign on the same post.
- Keep it to one plate per sign where you can, so drivers can read it at speed.
Main signs for private roads are in our private property road signs guide and speed limit signs guide.
Frequently asked questions
What is a supplementary plate?
A smaller sign mounted under a main regulatory or warning sign to add a time, distance, vehicle type, exception or reason.
Can I put my own number on the plate?
Yes. Plates with a blank number in the name, such as the distance, GVM and height plates, are printed with the number you supply when you order.
Will my signs arrive before Christmas?
Every sign is made to order. Order by Wednesday 16 December (NSW, VIC, QLD, SA) or Wednesday 9 December (WA, NT) for delivery before Christmas. Every sign is 30% off until 31 December.
Browse the full range in road and traffic signs.
Related: Roadwork and traffic control signs ยท NSW road and parking signs
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