Before you dig: find the NBN cable first, and what to do if you cut it

When an NBN cable gets cut, it is usually by someone doing an ordinary job in the yard: a fence post, a garden bed, a stormwater trench, a new driveway. Much of it is avoidable with a free enquiry and a few minutes spent finding the cable on the ground. When it does happen, the first hour decides how quickly it is fixed, and if the damage turns out to be on your side, that is fibre optic cable repair that finds the break and says whose side it is on.

What is Before You Dig Australia (BYDA)?

Before You Dig Australia, BYDA for short, is the free national service for finding out what is buried at a site before you dig. It used to be Dial Before You Dig: the state services became one national organisation in July 2022. You lodge one enquiry, and the companies that own pipes and cables at that spot, the asset owners, send you their plans.

Lodging works like this, from BYDA’s own guide to its free plans (opens in a new tab) (checked 18 October 2026):

• It is free to lodge. You register on the BYDA website, search the address and draw the area you plan to dig on the map.
• You describe the job: the dates, the type of work and who it is for, so the owners can tell what you will be near.
• A confirmation email comes first, with your site details and a list of the asset owners and their contacts.
• Then the plans arrive from each owner, typically within minutes, but BYDA says to allow up to two business days. If an owner has not answered, contact them directly before you start.
• Plans expire. The date is on them. If the job runs past it or changes, lodge again.

Lodge it before the tradesperson turns up, not on the morning. BYDA’s advice to homeowners is to decide who will lodge the enquiry before any contractor starts work on your property.

Do Before You Dig plans show the NBN cable on my property?

Not reliably, and never exactly. BYDA says its plans are indicative only and do not pinpoint where an asset is. They may show the lead-in to your house, but they may not contain specific details inside your property boundary, and anything installed privately is not on them at all.

That matters because the cable people hit is the lead-in, the single cable from NBN’s pit in the footpath across your yard to the house. The network in the street is usually drawn well. The stretch under your lawn is the part least likely to be drawn where it really runs. On older streets, where the records go back to the copper days, our technician’s rule of thumb is that if the plan says the cable is here, it is often over there.

Three things are never on the plans:

• Cables you or a previous owner put in: a data cable to the granny flat, the power to the shed, garden lights, irrigation. BYDA’s answers to common questions (opens in a new tab) say privately installed services will not be shown.
• The depth. BYDA warns that pipes and cables can be buried just below the surface. We have been called to fibre in a pipe barely a hand’s width under a garden bed, and to a cable buried straight in the soil with no pipe at all.
• Anything that moved. A pipe laid properly can be lifted by roots or shifted by an earlier dig.

Most lead-ins are laid in a pipe at a set depth, and NBN conduit installation gives nbn’s own figures. You still cannot count on yours being there, and on fibre, some aren’t in a pipe at all.

Pick a view

What the plan shows What is in the ground Digging safely

Pit Boundary House

The planindicativedig by hand hereIn the groundGarden bedcable to the shed: on no plan

What the plan shows

The plan shows the network in the street. The lead-in may be drawn as a straight line from the pit to the house, or not drawn at all, and nothing a previous owner put in is on it.

What is in the ground

The real lead-in bends, and runs shallow under the garden bed at the boundary, right where a spade or a fence post goes. The cable to the shed is not on any plan.

Digging safely

Find both ends, mark the line between them, and dig by hand near it until you have seen the pipe.

Did you know some NBN fibre is buried with no pipe at all?

You can lodge a Before You Dig enquiry, find both ends of your lead-in and still put a spade through it. In a couple of weeks we had three or four calls from people who had done exactly that. In each case the fibre wasn’t in a pipe. It was lying in the soil, just under the surface.

It isn’t a one-off. When the old pipe from the street to a house is blocked or broken, nbn’s construction standard gives installers several ways to clear it or get round it so the fibre can be connected on the day. One of them is a shallow buried drop cable: the fibre laid straight in the ground, 150 mm deep, on your side of the boundary only (NBN-CON-STD-4238, section 11.2.5).

When the old pipe is blocked

Try to clear it

Flush it with water

NBN-CON-STD-4238 s11

Pull the old cable through

NBN-CON-BI-4760 s7.2

Dig down and repair the pipe

NBN-CON-STD-4238 s11.2.1

Or go round it

Y connector into the old pipe

NBN-CON-STD-4238 s11.2.4

Pipe fixed along the surface

NBN-CON-STD-4238 s10.8

Fibre 150 mm deep, no pipe

Your side of the boundary only

NBN-CON-STD-4238 s11.2.5

150 mm spade blade

When the old pipe is blocked

Try to clear it:

1. Flush it with water (NBN-CON-STD-4238 s11)
2. Pull the old cable through (NBN-CON-BI-4760 s7.2)
3. Dig down and repair the pipe (NBN-CON-STD-4238 s11.2.1)

Or go round it:

1. Y connector into the old pipe (NBN-CON-STD-4238 s11.2.4)
2. Pipe fixed along the surface (NBN-CON-STD-4238 s10.8)
3. Fibre 150 mm deep, no pipe, your side of the boundary only (NBN-CON-STD-4238 s11.2.5)

150 mm is less than the depth of a spade blade. Edging a garden bed, laying turf or digging a hole for a plant is enough to reach it.

When a buried cable like this is cut there’s no pipe to pull a new one through. It’s either joined where it broke, or dug out and replaced along its whole length. Who repairs it and who to ring is the same as for any cut lead-in, below.

If your fibre went in or was repaired in the last few years, ask whether the technician used the old pipe. If the cable goes straight into the ground at the wall, with no pipe around it, treat the whole run as if it is just under the surface: find both ends, mark the line and dig by hand near it.

We filmed the cables we found, and how shallow they were.

How does the NBN cable usually get cut?

Almost always by someone doing a normal job who did not know the cable was there, or thought it was dead. These are the jobs behind the calls we get:

• Fences and retaining walls on the front boundary, right where the lead-in crosses into the property. One fencer thought the cable was a tree root.
• Plumbing and stormwater trenches dug out to the street, often with a pick.
• Driveways, gates and carports. A core drill for a gate post can go straight down through the pipe and the cable inside it.
• Garden beds, edging and new turf: a spade, a mattock or a rotary hoe in soft ground over a shallow cable.
• Excavators digging for new power mains, a pool or a second dwelling.
• Owners clearing up, who pull out a length of old pipe and cable thinking it was left over from years ago.
• Indoors, during a renovation: joinery screwed over the cable, or an electrician cutting what looked like a spare.

Two things make it easy. The cable is often shallower than anyone expects, and it does not look like anything important.

How do I find my own NBN cable before I dig?

Find the two ends, the pit out the front and the point where the cable reaches your house, and assume it runs between them until you have proved otherwise. Then dig by hand anywhere near that line.

1. 1

   Find where it reaches the house

   On fibre to the premises it ends at a box on the outside wall. On HFC it is a small wall box on the outside of the house. On the copper types it is often a small box near the power meter, or a cable coming up under the house or through the slab.

2. 2

   Find the pit

   It is usually in the footpath or the nature strip out the front, often beside the water meter, and sometimes shared with the house next door. Find it, but leave the lid on: the pit and everything in it is NBN's.

3. 3

   Look under the house

   With a torch, look along the front wall for a white pipe with a black cable in it coming in from the street. Where it enters tells you which way it runs.

4. 4

   Ask whoever built it

   On a newer house, the builder or the previous owner may have a photo of the trench or a plan of where the pipe went. Ask before you guess.

5. 5

   Mark the line, and treat it as a guess

   Spray paint the line between the two ends. A lead-in does not always run straight, so dig by hand near the mark, carefully, until you have seen the pipe.

6. 6

   Still cannot find it? Get it located

   A pipe-locating service pushes a rod with a metal trace through the pipe and follows it with a detector, then marks the ground. BYDA also suggests a skilled locator for assets on private property. It beats digging holes for an afternoon in the wrong place.

One warning from a real call. If the cable comes in on a pole, do not dig around the base of it. A pole carrying cables is under tension, and taking the soil away, then letting rain into the hole, can bring it down.

Can I dig near the NBN cable myself?

Yes. On your own land you can dig, and digging is the one part of a lead-in job that needs no registration. The cable is another matter: on fibre, HFC and the copper connections the lead-in is part of NBN’s network, even under your yard, so you dig around it, never through it.

Who owns the NBN lead-in to your house sets out where the network ends on each connection type, and it is the page to read before an argument with a builder. The short version for anyone with a spade:

• Dig to the cable, not past it. Once you have seen the pipe, work around it by hand.
• Plan around it, not over it. If the pool, the slab or the new driveway has to go where the lead-in is, the lead-in has to move first, and that is planned before the machine arrives. A knockdown or a rebuild is the same: pulling on a live fibre lead-in can damage what it is connected to in the pit.
• If you are laying a new pipe for it, the route, the depth and the bends all matter. The conduit page has the specification, and lead-in cable installation covers the cable side of the job.

What should I do if I cut the NBN cable?

Stop digging, photograph everything before it is touched, and get the person whose name is on the internet account to ring their provider. Do not tape it, join it or pull it out.

1. 1

   Make the site safe

   If you have hit power or gas as well, keep everyone back. BYDA says to ring 000 in a life-threatening situation.

2. 2

   Photograph it before anything moves

   The cut ends close up. The pipe either side. A wide photo from the pit looking back at the house. The box on the outside wall. The NBN box or the modem inside, with its lights showing.

3. 3

   Leave the ends alone

   Tape over a cut cable does not last, a home-made join on it makes the repair harder, and the lead-in is the network's to repair, not yours or your tradesperson's.

4. 4

   The account holder rings their provider

   Providers will only talk to the account holder, so a contractor who cut it needs the owner or the tenant to make the call. Report it as cable damage, and send the photos.

5. 5

   Say who did it

   If a contractor, the council or another utility cut it, give the provider their name, their business and the date. The network repairs the cable and can recover the cost from whoever caused the damage, which is called recoverable damages.

6. 6

   Keep a record

   Your photos, the times and who you spoke to. BYDA tells anyone digging to keep a record if they damage an underground service, because asset owners may seek compensation for the damage.

If you were the one digging and you had Before You Dig plans, they list the asset owners and how to contact them. Follow what the plans pack says about reporting damage as well.

Who do I ring first on each type of NBN?

Your provider, on every type. NBN is a wholesaler, so the repair is booked through the provider whoever cut the cable. What changes from one type to the next is how far the network’s cable runs and what is worth photographing.

If the cable is cut in the yard: whose it is and who to ring, by type of NBN

Type of NBN	The cable in the yard	The network's, up to	Ring first	Also photograph
Fibre to the premises	Fibre, in a pipe	The box on your outside wall	Your provider	The outside box, and the lights on the NBN box inside
HFC	Coax cable	The wall box on the outside of the house	Your provider	The wall box, and the lights on the NBN box inside
Fibre to the curb	Copper	Where it ends at the house	Your provider	The NBN box by the phone socket, with its lights
Fibre to the node	Copper	Where it ends at the house	Your provider	The modem, with its lights

On fibre to the curb, say whether the cable was cut or pulled. A lead-in dragged hard from the pit end can damage NBN’s unit in the pit, which serves more than one house, and the provider should know that before it books the repair.

Not sure which NBN you have? Which NBN connection you have, and how to tell shows the boxes for each type, and a photo of what is plugged in inside settles it. If the lights on the box are the question, what the NBN box lights mean has each one.

When the damage is inside the house, or between the box on the outside wall and the box inside, it is not the network’s lead-in. On fibre, that lead between the two boxes is the property’s own cabling, and that is a repair we do.

When do you need a technician, and when don’t you?

You do not need us for a cut lead-in. It is the network’s cable, so it goes to your provider with the photos, and NBN repairs it. You do not need us to lodge a Before You Dig enquiry either: it is free and anyone can do it.

You do need someone like us when the job is on your side of the boundary:

• The fibre lead between the two boxes is damaged, in a wall, a ceiling or under the floor. That is fibre optic cable repair.
• The pipe is crushed or missing, so NBN’s installer has nothing to pull a new cable through. A broken section is replaced to the specification on the conduit page, usually without digging up the whole run.
• The route has to change for a pool, a slab or a driveway. The new conduit goes in before the machine arrives, so it is one job instead of two. Where the box on the wall moves too, that is NBN box relocation, the version of the job that needs NBN’s lead reordered.
• Nobody can find the pipe, or the box at the house goes nowhere you can see.

On a job where we dig, we lodge the Before You Dig enquiry ourselves first and check the plans before anything goes in the ground. Not sure which of these you are looking at? Send us a message with the photos, or ring 02 9188 1577.

If your provider will not act on a cable that is part of the network, the ombudsman takes complaints about providers. How to complain about an NBN fault walks through the order: your provider first, then the Telecommunications Industry Ombudsman.