How will SMETS1 meters be updated when SMETS2 is rolled out?

In your discussion on SMETS1 vs SMETS2 you indicate that SMETS1 meters will be made DCC compliant by end 2019 but you do not make it clear if this will be a hardware fix done by an engineer at the house or a remotely activated software download. (I mean in respect of the meters you are currently installing).


Best answer by Nancy_OVO 22 August 2018, 16:10

Updated on 14/05/21 by Jess_OVO


The Smart Data Communications Company  (DDC) upgrade of S1 meters is carried out remotely. The info below was taken from this topic guide we made to explain this process of upgrading S1 smart meters: 

Getting your S1 smart meter onto DCC - your guide


When you switch suppliers with S1 meters, we can't always communicate with your meters. Take a look at S1 meters we can communicate with for more information. 

What is this update?

It's a nationwide update to S1 meters to make them automatically send readings if they had stopped communicating due to a change of supplier. The process it goes through is Enrollment & Adoption (E&A), the output of this means both S1 and S2 meters are controlled/managed by the DCC.

Why do these smart meters need to be updated?

To get the full benefits of smart meters, the government has decided that there should be one new unified smart meter data network. This makes smart meters work more effectively with all energy suppliers, improving the efficiency of the grid and helping us all to cut carbon emissions.

Once your S1 smart meter has been updated to this single network, you’ll also be able to switch suppliers without your meter losing its smart features. Smart meters automatically send meter readings to your energy supplier. This means your bills are more accurate, and you can see how much energy you’re using your online account or OVO app (download for Android or iOS) – It’s also shown on your In-Home Display (IHD)

Until your meters have fully gone through the E&A process, they will become dormant. Therefore, you’ll need to provide readings to make sure you receive accurate bills. 

What timescales to expect for my meters to be enrolled?

This table shows the expected delivery date depending on the Meter Manufacturer. 

Meter Manufacturer MSN format Fuel Expected migration to Smart
Secure YYP Electric Started January 2021. Expected to complete by March 2022.
  G4P Gas  
Elster YYK Electric Already started. Planned completion October 2021.
  G4K Gas  
Aclara YYM Electric Already started. Planned completion October 2021.
  G4F Gas  
Itron YYS Electric Already started. Planned completion October 2021.
  G4 Gas  
L+G YYL Electric Started May 2021. Expected completion September 2022.
  ZYYQ Electric  
  ZYYN Electric  
  E6S Gas  

How can I easily identify if the meter is Secure?

Secure Electric Meter Serial Numbers will start with XXP (eg 18P) and Gas Meter Serial Numbers will start with G4P. 


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63 replies

Userlevel 7
Badge +4

No worries.

For the most part, you won’t see many differences in how an S1+ meter operates compared to an S1 meter. The biggest difference will be the fact that an S1+ is connected to the supplier via DCC and can therefore be operated with any supplier, even those that didn’t use the same meter brand (or the same networks) in the S1 days. All S1 meters will eventually be S1+ but there’s very little that you can see happening yourself as it’s all in the background.

Until then, regular S1 meters will only work with suppliers that have the same meter brand and use the same network as the supplier who originally installed the meter. Other than that, there’s not really much that will change. Your meters will still record your usage and submit it to your supplier in pretty much exactly the same way as before (albeit via a slightly different route) and your IHD will continue to work in exactly the same way it does now.

Userlevel 1

I do appreciate that.   However, is there any difference I will see in operation?

Userlevel 7
Badge +4

The one thing to be aware of is that it’s impossible for an S1 meter to ever be upgraded to a true S2 (which OVO’s Smart Meter Friend helpfully reminded me about recently). That’s because it’s ultimately still S1 hardware and the firmware updates mainly just do some magic tricks that allow the meter to be managed via DCC, but is still S1 firmware.

That’s why I like to call these meters SMETS1+, or S1+ for short. Because erm… What else can we call them? But yes, they can run like an S2 to an extent - especially the ability to switch supplier and keep using the same meters with smart features remaining enabled.

If they’re no longer pure S1 and they’re not proper S2, then it kinda make sense to consider them S1+. I got the idea for the name from railway level crossings, but it’s never been made an official term in the spec. Not yet at least anyway…

The only way to get pure and true S2 is to swap out the hardware for full S2 across everything. There can be edge cases where this becomes necessary - such as if every possible attempt to get an S1 to do the firmware upgrade and then get it working with DCC as S1+ completely fails - but these are the exception rather than the norm. It’s less disruptive to try to the remote firmware updates and remotely migrate the existing meters to DCC than it is to physically replace all of them.

Since these things don’t last forever anyway, the number of S1 meters in service will eventually begin to drop off over time as they get replaced for any reason - such as faulty meters or re-certification stuff. In actual fact, some of the earliest S1 meters are probably approaching somewhere around halfway through their service life as well...

Userlevel 7

Welcome back, @TWSaab!


Interesting to hear that the ‘Estimated Usage’ figure has reset. There’s a number of reasons why this might have happened, you might have started a new plan or had a unit rate change if you’re on a variable plan. It could also be due to your meter going through the remote upgrade. 


This remote change won’t be noticeable on your online account and won’t make a difference whilst you are still with OVO. If you’re planning a switch and want to confirm that your meters have updated before you do, it’s worth reaching out to our Support Team, or sending us a PM on here (including your full name, OVO account number and  full address) and we can take a look. :grinning:

Userlevel 1

Hi again,

I have noticed that the ‘Estimated Usage’ has reset and is now reading very low £ on the IHD.  Does this mean that I have now been migrated onto SMETS2 (or SMETS1+) and the meter should be acceptable to all suppliers?

Userlevel 1

Thanks for that.

Sorry, I meant that I did not want them to go dumb if I changed supplier as they are in an awkward location to read.

From what you say if I change supplier the new supplier will be responsible for the update, which should still be completed by Summer 2021.

Userlevel 7
Badge +5

Hi @TWSaab - yes, that time-scale is correct.

I haven’t heard of any site where the SMETS1 meters have gone dumb as a result of the software upgrades.

There are actually two stages to this:

  • The manufacture sends the code upgrade for your meter(s) and Communications Hub.
  • The upgraded meter is migrated across to the National Smart Meter Network.

If your SMETS1 meter is currently operational, then it’s unlikely that you will detect any difference when these two stages are completed.

Your current Energy Supplier is always responsible for the meter code and upgrades. If it were not so, then a Supplier would have a hold over you, even if you were in dispute. That’s not permitted under Ofgem regulations. You are always free to switch.

Userlevel 1

I see there is now an Ovo document saying SMETS-1 meters will be upgraded by ‘Summer 2021’ as an OTA upgrade.  My meters are in an awkward location for reading so I do not want them to go dumb, this is the main reason I changed to smart metering.   

Two queries:

  1. How will I know when my meter has been upgraded?  Will I be advised?
  2. If I change supplier to another which can read SMETS-1 meters before it is upgraded  will it still have to be upgraded by Summer 2021, and who will be responsible for the upgrade?
Userlevel 7
Badge +5

Thanks for the clarifications @Apial

Nancy is still correct in asserting that these issues can be readily resolved. However many Energy Suppliers are involved, there is still only one central database which holds your meter data. For electricity, that database is ECOES


For the sake of others who come across this Topic at a later date, may I just explain the way in which the strategy has evolved for handling differing tariffs at the same site:-

We used to require two separate meters, where one registered the standard electricity usage. The other one was attached to a time-clock and fed devices like storage-radiators on an Economy-7 tariff.

That progressed to a situation where a single digital meter could record both standard and E-7 uses. Those still required manual reading however.

The current Smart Meters (both SMETS1 and SMETS2) have software control for 4 or 5 different tariffs which can be recorded separately. In addition they have an Export Tariff register for electricity sent back to the National Grid.

Currently we don’t use much of the multi-tariff capability of Smart Meters, but that’s about to change.

Another Supplier, Octopus, already offer a variable tariff at different times of the day. Soon this will become possible through all UK-based Suppliers.

The regional Distributed Network Operators have put together a DUoS tariff (Distributed Use of System) which has three bands of charges labelled Red, Amber and Green. This will enable customers to choose when to use electricity with all three pricing structures held within the Smart Meter.



Yes that’s right. But OVO only handle my Solar panel FITs payments. The supply  problem is between Eon and Ebico. 


Ive emailed the FITs team and I’m waiting for their reply. 

Userlevel 6

Hi @Apial - I’m not sure what you mean about the time registers being reversed? Do you mean the night was clocking during the day and vice versa? If so, it shouldn’t be too difficult to recalculate the bills based on the correct day and night unit rates. Please give us a ring (0330 303 5063), or send us a message on Facebook with your account number, full name and DoB and we can look into this for you.

See this.


The upgrade process is clearly flawed. DCC and Ebico have failed in their duty to correctly implement the switch. 


My meter time registers were reversed. I am potentially being billed for £500 extra. 


It could cost me anything from £300 to £1650 of lost solar export payments over the remaining 15 years of FITs. 



Userlevel 6

Hey @TWSaab, sorry about the radio silence, there is no further update currently, as soon as there is we’ll update here! 

Userlevel 1

This thread seems to have gone very quiet. 

Any chance of a response from Ovo on the MOC dates?   The June date would certainly avoid any cold weather interruptions if that was still a concern.   One assumes Ovo must be involved and informed even if the update is carried out by the manufacturers.

Userlevel 1

Not doubting you but has there not already been a period of testing?   The organisation (or lack of) of this project is becoming more unbelievable.  

The article gives the proposed timings of all three capability phases with the MOC being when they are planning to update the Secure meters and migrate to DCC?   That is what it appears to be following the consultation which closed last November.   Is this not correct?  Did the IOC not start last November?

The total lack of information from the suppliers leaves one grasping at any other information available.   

Userlevel 7
Badge +5

Erm @Russell these dates are not what you might at first suppose.

The announcement states that there are three capability phases, and then gives timings for the Middle one. There is no indication here of how long is required from the time of the MOC to the dates when customers’ readings will be handled by DCC within the Final Operating Capability.

I would expect there to be a period of testing first.

Userlevel 1

There is some information concerning expected dates in the link above

SMETS1 meters will be migrated to DCC in five batches over three capability phases. Once the capability is made ready on the dates below, the migration will happen within the following months.

  • Middle Operating Capability (MOC)
    • 15 Mar 2020 - Elster Honeywell meters currently operated by MDS (Morrison Data Services)
    • 28 Jun 2020 - Secure meters operated by the Secure Meters group

So for OVO from the end of June onwards.

Thank you for that information.   It is more than I have ever been able to get out of OVO despite some of it being quite old.  

It will be interesting to see if they keep to the programme and start in June this year.  It would also be interesting to have some sort of estimate of the time the update will take


Userlevel 1

There is some information concerning expected dates in the link above

SMETS1 meters will be migrated to DCC in five batches over three capability phases. Once the capability is made ready on the dates below, the migration will happen within the following months.

  • Middle Operating Capability (MOC)
    • 15 Mar 2020 - Elster Honeywell meters currently operated by MDS (Morrison Data Services)
    • 28 Jun 2020 - Secure meters operated by the Secure Meters group

So for OVO from the end of June onwards.

Hi @Transparent 

I really don’t think anyone would want to jepodise security but I do share @TWSaab’s frustration re the lack of communication about this.

I got a smart meter fitted in Nov 2016, noone explained before it was fitted that it would become dumb as soon as I switched, or that they weren’t compatable with other devices in the way my old one was (e.g. the loop system), or that the gas meter would have a display on the side - so taking a meter reading would involve feeling for the number 9 button, sliding your phone in the small gap quickly and taking a picture, hopefully before it switches to the next display. Had I know all these things I personally would never have got one so I’m feeling quite conned. My “Smart meters” have been dumb since around July 2017, and since then I’ve been told there will be a magical upgrade which will fix it, but  despite keeping asking as many people as possible, the total lack of communication as to when this may actually appear is frustrating. The only information I have had is from internet searches which provide various “deadlines” that have all been missed. As someone who has since left the company that fitted the meter concerns include will anyone actually be responsible for upgrading mine. The current company I’m with say they can’t read it so it’s unlikely to be them and why would the past company care.. I’ve just arranged to switch again and despite the comments on other posts on here saying EON use the same meters that I have so will be able to read mine they’re still saying that they won’t until it gets upgraded which will take “some time”.

I’m not blaming you for any of this, and I understand you’re just trying to help without causing any issues. I’m just trying to explain why I’m desparate for someone to give us some information.

Userlevel 7
Badge +5

I’m really not sure I should be saying much more on an open Forum @TWSaab. Knowing which party is effecting an upgrade is itself a weakening of the security, and I can’t see what advantage is to be gained by there being a more detailed explanation provided to end-users.

I’ve received a number of remote software upgrades to my meters and Comms Hubs over the past 10 months. But although I know roughly how the process works, I would hold OVO’s engineers in low regard were they to be explaining my upgrades on this open Forum.

Worse still would be to provide advance notice of when such transmissions were to be anticipated!

You can check the dates at which proposals and decisions were made about the SMETS specifications by looking at DCC’s and Ofgem’s online archives. There is some additional data on the BEIS site. Most of the SMETS2 system we are now implementing was enacted through Parliament in 2013/14 when Sir Ed Davey MP was Energy Minister in the coalition government.

Userlevel 1

Thanks, but I was not after any information which might jeopardise security, just basic stuff like who will be carrying out the upgrade.  

As it was supposed to have been started last year and should already be underway the ‘substantial technical hurdles’ should already have been overcome.  Otherwise it would be good just to be told that there was a problem and what a new target date might be.   Surely the communication network frequency was decided long ago and if the Secure units do not have a transceiver operating at the right frequency why would Ovo say it was to be an OTA upgrade?

For something which should be in progress it seems to be a mess with no updates to customers from those who should be doing it.   Basic information on a delay would have changed decisions on supplier I have just made.

Userlevel 7
Badge +5

Firstly, @TWSaab I don’t expect there to be a great deal of information made available to end-users about the 3rd and final stage of upgrading meters to SMETS2 functionality. There are security aspects to consider and it is important not to provide information to potentially hostile 3rd-parties who may wish to disrupt our UK domestic energy supplies.

Secondly, there are some fairly substantial technical hurdles to overcome. For example, in the Northern Territory, SMETS2 Communication Hubs are to communicate with the data network operated by Arqiva. This functions at a frequency of 400MHz which was released from the old ITV analogue transmitters.

However, I don’t believe that any of the SMETS1 meters from Secure contain a transceiver operating at that frequency. As far as I know they all used the same wavebands as mobile-phone GSM signals.

Whilst I have a technical interest in knowing how this anomaly is to be overcome, I don’t really want that information to be freely available on an open public forum!

Userlevel 1

Whilst I agree that failures in winter would not be good failures at any time are not good if it affects the power supply.  However, I don’t think there are too many meter suppliers (and as far as Ovo are concerned they are all Secure?) so it should not have been difficult to have rigorously tested the update long ago and be carrying it out by now.  

It would be good to have firm information as to who is carrying out the upgrade - is it the original supplier/installer or the manufacturer etc?  They must know by now.   If the update is OTA it is difficult to understand what the delay is, after all Samsung manage it on millions of phones regularly.   They seemed to have enough engineers when they convinced you to fit the meters and, assuming the update is fully trialled, they should need less to correct the occasional problem.

What is the situation if you change supplier, who is responsible for the update then?   For something which should already be happening things seem very vague at the moment, or maybe I have missed any information on the subject from suppliers.

Userlevel 7
Badge +5

I would expect the software upgrades to SMETS2 functionality to be primarily the responsibility of the meter manufacturers. They will have been collating errors and fixes over the past several months and incorporating the necessary software changes within the SMETS1 upgrade code.

However, they don’t a force of field engineers to respond if something goes awry. So I hope that a common sense approach is taken, such that each Energy Supplier can ensure that they have enough engineers in each geographical area as the upgrade is undertaken.

I also hope that any upgrades will be delayed until Spring. We really don’t want the possibility of homes being left without energy in the middle of winter!

Thanks for clarifying the quotation, @taffy. It was the "DCC compliant" bit which threw me. But I understand now I can see it in context.

And it's good to hear from @Nancy_OVO that the upgrade from SMETS1 will be undertaken remotely. The timescale of the end of 2019 sounds about right for that too.

I tend to agree with you that the original roll out of Smart Meters wasn't actually particularly smart. The Government seems to have trusted the Energy Suppliers to agree compatibility, based on a common set of commands. But they, of course, took the opportunity to lock customers into themselves by implementing the commands in different ways!

By contrast the SMETS2 protocols are far more of an open standard. Any design engineer can develop an Auxiliary Load Control Switch, and have it run from a SMETS2 meter. So if you fancy returning to your profession and designing a low-voltage storage unit to run all your house lights on electricity bought at the lowest price-point, then you're free to do so 🙂

Hi @Transparent 

Just wondering if there’s any update on when and who will be completing these updates. My meters were fitted by OVO, although I’m no longer a customer and so far don’t seem to have regained their smart features despite the “end of 2019” deadline having passed.