Replacing an EFM Circuit: A Practical Plan

An EFM circuit is rarely just a connection. Over the years it gathers static IP addresses, firewall rules, VPNs and phone systems that depend on it. Replacing it well means recording all of that first, then choosing a successor that fits the site and running the two side by side before the old one is ceased.

By Chris Byrd 5 November 2026 Connectivity & WAN

Four steps to a clean replacement

Record what the circuit carries

Note each circuit's reference, number of pairs, speed and contract end date, and everything that depends on it: static IP addresses, VPNs, firewall rules, voice and remote access.

Choose the successor per site

Business FTTP where EFM was simply the best connection available; Ethernet fibre where the site relies on symmetrical, uncontended capacity.

Plan addressing and routing

Decide whether the site keeps its IP addresses or moves to new ones, and update everything that refers to them, including partners' allow-lists.

Overlap, move, then cease

Install the new line alongside the EFM circuit, move services across and test them, and give notice on the EFM circuit only once the site is running on the new line.

Why plan now rather than at renewal

EFM depends on copper pairs, and Openreach is withdrawing copper-based products exchange by exchange as full fibre reaches each area. Suppliers set their own dates for EFM, so the contract and the supplier's notices are the authority for any one circuit. Waiting for that notice leaves the least time to survey, order and install a replacement, which for an Ethernet circuit can mean weeks of build.

Notice periods matter too. An EFM contract often runs on after its minimum term and needs notice to cease, so the new line should be in service before that notice is given, not after.

Choosing the successor

Start with why the site has EFM. If it was the only symmetrical option when the line went in, business FTTP will now usually beat it on speed in both directions; our comparison of EFM and FTTP sets out where each fits. If the site relies on uncontended capacity and business repair terms, a fibre Ethernet circuit is the direct successor, and our guide to ordering a leased line covers surveys, wayleaves and build.

Where full fibre has not reached the address yet, SOGEA is a stopgap rather than a replacement: it removes the phone line but still runs over copper to the premises.

Netavo provides business FTTP at up to 2300M and fibre and Ethernet connectivity from 100M to 10G, with mobile failover available as a second path on any of them.

Check what can replace EFM at an address

Enter the site's postcode to check FTTP and SOGEA availability. SOGEA still uses copper to the premises; it is not full fibre. Ethernet is quoted separately.

You can also use the business full fibre checker. For an Ethernet quote, work with us.

An EFM estate review for partners

Resellers, IT providers and MSPs managing EFM circuits across customer sites can send Netavo their list of sites. We will confirm the fibre and Ethernet access available at each address, with pricing. Netavo designs, delivers and operates network solutions for partners.

Ask about an EFM estate review →

Common questions

What replaces an EFM circuit?

Business FTTP for sites that used EFM as the best connection available, or a fibre Ethernet circuit for sites that rely on symmetrical, uncontended capacity. Netavo provides both.

Can I keep my IP addresses when replacing EFM?

That depends on who holds the addresses and how they are routed, so it should be settled before the new line is ordered. Netavo plans addressing and routing as part of moving a site.

Will there be downtime when EFM is replaced?

Not if the new line is installed alongside the EFM circuit and services are moved across before the EFM circuit is ceased. Netavo plans replacements that way.

Is SOGEA a replacement for EFM?

SOGEA is a stopgap rather than a replacement, because it still runs over copper to the premises. Netavo can confirm whether full fibre reaches a site.