Eversource and National Grid Implemented System Upgrades that affect ALL Residential and Commercial Accounts

Eversource and National Grid have implemented significant system upgrades, affecting all residential and commercial accounts. These changes include new account number formats and essential timelines for customers to follow. Learn about the impacts of these upgrades, how to manage your new account numbers, and steps to ensure a smooth transition with your energy suppliers.

Here is what you need to know:

Eversource ELECTRIC (NSTAR: BE/CA/CM) System Conversion

What’s Happening?

Eversource is moving to their new OMNI System.

What is the Impact?

  • Eversource/NSTAR will be consolidating their utility duns from 3 to 1.
  • Eversource/NSTAR will replace its current Account Numbers with Contract Accounts (numerical with 11-digits) and an 8-digit POD ID
    • One-time 814 Change transactions will be sent with the new Contract Account and POD ID
      • Your SUPPLIER will receive a one-time conversion file once conversion is complete that include old and new numbers.
  •  For a period of 45 business days after conversion (July 26), Eversource will accept (not reject) 814 Request if the REF*12 reflects the old Eversource account number instead of the new Choice ID (Interval Data Requests Using Old Acct#).

What is the Timeline?

Implementation Date: June 4

Eversource NATURAL GAS – (ComGas/NStar) Billing Conversion Project – Account Number Changes

What’s Happening?

ComGas (Eversource EMA) has been working on their OMNI System conversion project and is in the process of converting their Customer ’s Current Account Numbers to a NEW Account Number/Format.

What is the Timeline?

Once conversion is complete, Eversource will continue to honor requests using the Old Account Number-Meter/Format for 45 Days, but it is encouraged to obtain the NEW Account Number-Meter as soon as possible, especially if you’re about to execute a new supply agreement as suppliers will need the new account numbers to successfully enroll the accounts.

  • The New Account Number will be available to the customer on June 4.
  • Customers received a Bill Insert in their May invoice advising customers if they already have an online account with Eversource that their new account number will automatically link to their online account.

All Com Gas LDC Account Numbers/Format will be changing as follows:

  • From the current format XXXX-XXX-XXXX-XXXXXXX
  • To the new format 73XXXXXXXXX-XXXXXXX

Com Gas Account Numbers will look similar to Baystate Account numbers:

  • EGMA/Baystate Account Numbers start with “71.” 
  • EMA/ComGas Account Numbers will start with “73.”

NEW Utility Email Contact information for both Eversource MA (fka ComGas /NStar) And Eversource Gas MA (fka Baystate)

Effective Immediately: Old email addresses for NStar inquiries and Baystate LDC inquiries are no longer available.



What is the Impact?

NGRID MA gas account numbers will also be changing. National Grid (Boston/Colonial/Essex) has been working on their C2C conversion project and is in the process of changing their customer ’s Current Account Numbers to a NEW Account Number.

What is the Timeline?

Implementation Date: May 28

  • Current Account Numbers, which are 10 digits long, were converted to NEW Account Numbers that are also 10 digits long but in a different format, with no numeric identifiers indicating if they are in the Boston/Colonial/Essex zone.
  • NGRID sent suppliers a list of their Current Customers new account numbers to be uploaded into their systems.

EDI and Historical Usage requests:

Any National Grid request submitted after 5/27 will need to be requested using the NEW account numbers. The customer can obtain their New LDC Account Number by looking up their account online once the conversion is complete, requesting a mapping sheet from their supplier, or reference the letter sent by NGRID providing the new account number after the conversion was completed on May 28.


The two largest utility companies in Massachusetts just completed system upgrades that impacted everyone. To continue purchasing electricity and natural gas through third party supply, you will need this information when going out to bid. The utility has provided this information through the mail, but we encourage you to reach out to your supplier (or ask us to lend a hand!) and request an electronic file mapping the old account numbers to the new ones to avoid any confusion now and down the road.

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Meet the Writer

Brian White
Freedom Energy Logistics
Municipal Program Director

Brian White brings two decades of experience to his role as Municipal Program Director at Freedom Energy. He advises and assists communities throughout the Northeast in optimizing their energy spend and achieving sustainability goals. Brian collaborates with cities and towns to meet their energy requirements and renewable objectives, leveraging existing relationships, and establishing new ones within the municipal community. Click here to read Brain’s full bio.

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