GUIDE · UPDATED 2026-11-07

Meter Collar Transfer Switches: Does Your Utility Allow Them?

Short answer: A meter collar transfer switch installs between your utility meter and the meter socket. Because it sits in equipment the utility controls, the utility must allow it — and rules differ from one utility to the next, even in the same state. Check your utility's electric service requirements or call its metering department before you buy.

What is a meter collar transfer switch?

A meter collar (also called a meter socket adapter or meter-base transfer switch) is a ring-shaped device that plugs into your existing meter socket. The utility meter then plugs into the front of the collar. Inside, the collar can disconnect your house from the grid and connect it to a generator or battery instead.

Common examples include the Tesla Backup Switch (used with Powerwall systems), ConnectDER adapters (used for solar, storage and generator connections), GenerLink (for portable generators) and the Enphase IQ Meter Collar. Because they avoid rewiring the main panel, collars can shorten installation time compared with a traditional transfer switch.

Why your utility has to approve it

The meter socket is the point where the utility's service connects to your home, and the meter itself belongs to the utility. Installing a collar means the utility (or an installer it authorizes) must pull the meter and break its seal. For that reason most utilities only accept specific, tested adapters — and some do not accept them at all.

Utilities publish these rules in documents usually called Electric Service Requirements, service standards or a "blue book"/"green book". Look for sections on meter socket adapters, meter collars or customer-owned generation.

How to check your utility's rules

  1. Open your utility's page on this site (see all utilities) for what we found and the official source links.
  2. Search your utility's website for "meter socket adapter", "approved meter collar" or "electric service requirements".
  3. Call the utility's metering or new-service department and ask whether your specific device and meter socket are accepted.
  4. Ask your installer to confirm the utility's acceptance in writing before you sign.

If your utility does not allow collars

You still have options. A licensed electrician can install a transfer switch (manual or automatic) next to your panel, or a listed generator interlock kit on the main panel for a portable generator. Some battery systems use their own gateway or backup interface instead of a collar. See our interlock vs transfer switch guide.

Frequently asked questions

Can I install a meter collar myself?

No. The meter belongs to the utility and is sealed. Removing it is normally done by the utility or an authorized, licensed installer after the utility has accepted the device.

Is the Tesla Backup Switch approved by every utility?

No. Acceptance is decided utility by utility. Some utilities accept it, some accept it only for certain meter sockets, and some do not allow meter socket adapters at all. Check your utility's service requirements or ask Tesla or your installer to confirm.

Does a meter collar replace an automatic transfer switch?

A collar performs the transfer function at the meter, so in many installations it replaces a separate transfer switch. Whether it is acceptable for your generator or battery depends on the device, your utility and local code.