Your meter and your billVerified 26 July 20266 min readShare

What a NEM12 file is, and what to ask for

What the file is, what to ask any retailer for, and why opening it in Excel breaks it.

A NEM12 file is your smart meter's own record: every half hour, how much you drew from the grid and how much you sent back. It is a plain text file with a .csv ending. Opened in a text editor it looks like rows of numbers starting with 200 and 300. It is not designed to be read by a person, and you do not need to read it.

Everyone in the industry uses the same format, which is why a file from your network and a file from your retailer both work.

What to ask for, in one sentence

"Twelve months of detailed interval meter data in NEM12 format, sent by email."

Each part of that is doing work:

• Twelve months covers every season. A battery behaves very differently in January and July, and a short file leaves us guessing about the half of the year you did not send.
• Detailed is the opposite of summary. Summary means totals, usually as a PDF, and no amount of arithmetic recovers half hours from it.
• Interval rules out the accumulation meter reading, which is a handful of numbers per quarter.
• NEM12 is the industry name for the format. Saying it usually saves a round trip.

Your right to it

You do not have to explain why you want it. Both your retailer and your network have to give you your own metering data on request. In practice you can expect around 10 business days, and up to four requests a year free before anyone can charge you. Beyond that, or if you ask for an unusual format, a fee may apply.

Do not open it in Excel

This is the one that catches people. Double clicking a .csv on most computers opens it in Excel, and if you then save it, Excel rewrites the file in its own way. Dates get reformatted, long meter numbers get rounded into scientific notation, and the file stops being a NEM12 file. If you save it as .xlsx it stops being a CSV at all.

If you want to look inside it, that is fine. Just do not save.

• Look, then close without saving.
• Or right click the file and open it with Notepad or TextEdit instead.
• If you have already saved over it, download a fresh copy. It costs nothing.

A .zip containing a single CSV is fine, we open it for you. A spreadsheet workbook is not, and we will say so rather than guessing at what is inside.

If your retailer is not one of ours

Every retailer has to do this, so the sentence above works with any of them. Look for "meter data request" or "metering data" in their help pages, or just phone and read the sentence out.

The other route is your network, which is the same company whoever bills you, and in some states it is much faster. Find your network.

What our upload errors mean

If a file does not work we tell you which problem it hit, not just that something failed. Here is what each one means and what fixes it.

• It looks like a meter-read file, not interval data. You were sent the NEM13 file, the quarterly readings. Go back and ask for the detailed or interval option.
• It is for a different meter. The meter number inside the file does not match the one on the bill you gave us. Common if you have two properties, or if the request was filled for an old address.
• We could not read it as a NEM12 file. Usually a file that has been opened and re-saved, or one that was cut short. Download a fresh copy.
• It is a spreadsheet export. Your portal also offers a plain CSV. Take that one.
• It is larger than we support. Export a shorter range. Twelve months is ideal.
• It stops before your latest bill. Networks and retailers lag a day or two behind, and sometimes more. A fresh export a few days later usually catches up.
• It does not quite line up with your bills. Either the file is for a different meter, or the export is stale. A fresh export usually lines up.

What we do with the file

1. Step 1

   Upload your bill

   We read what you pay now, exactly, from your own bill.

2. Step 2

   We price every plan in your area

   Every plan in the government's open plan data, priced on your use.

3. Step 3

   Stay or Switch

   If staying put is the better plan, that is what the report says.

We check it is really yours by matching the meter number against your bill. We keep the half-hourly numbers with your report and delete the file itself the moment we have read it. You can delete the numbers too, any time, from your report. Our privacy policy spells this out.

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