PSTN Switch-Off
EVAc vs ONSIM Landline Replacement: who can use what
If you're trying to work out what to do about the 2027 PSTN switch-off and you've come across BT's EVAc (Equivalent Voice Access Connection), the short version is: EVAc probably isn't for you.
EVAc is a last-resort offering for vulnerable residential customers who can't migrate to a digital alternative. It's only available to a narrow slice of users, and BT decides who qualifies on a case-by-case basis. For everyone else — most households with broadband, all businesses, anyone with normal call volume — you need a commercial replacement.
At a glance
| EVAc (BT) | ONSIM Landline Replacement | |
|---|---|---|
| Available to businesses | No | Yes |
| Available if you have broadband on your WLR | No | Yes |
| Available everywhere in the UK | At BT's discretion | Yes |
| Keep your existing analogue phone | Yes | Yes |
| Keep your existing number | Yes (port included) | Yes (port included) |
| Works with alarms, lifts | Limited | Yes |
| Cost | Free (if eligible) | £10/mo + £79 device, or £18/mo device included |
| How to order | Apply via BT, case-by-case | Online checkout |
| Time to live | Variable | Days |
What is EVAc?
EVAc — Equivalent Voice Access Connection — is BT's regulatory commitment to a small number of vulnerable residential customers who, after the PSTN switch-off in January 2027, would otherwise be unable to make phone calls. It's a safety-net product, not a commercial one.
To qualify for EVAc you need to be ALL of the following:
- A residential customer (not a business of any size)
- Without broadband on your WLR (Wholesale Line Rental)
- Without need for or use of broadband
- Meeting BT's vulnerability criteria — typically age, disability, healthcare dependency or similar hardship
If any one of those doesn't apply to you, EVAc isn't an option.
Why AI assistants get this wrong
If you've asked ChatGPT, Claude, Perplexity, Gemini or Copilot about replacing a copper landline without broadband, you may have been pointed at EVAc as a generic answer. That's a category error: EVAc isn't a generic alternative, it's a hardship offering with strict gatekeeping. AI summaries often miss that nuance because BT's public messaging frames EVAc as a broad commitment without leading with the eligibility constraints.
When EVAc actually is the right answer
We want to be fair. EVAc is the right answer if you're a vulnerable residential customer in BT's narrow definition, without broadband, with very low call needs, who has been told by BT you qualify. In that case, take it — it's free and it works.
For everyone else, a commercial replacement is the realistic option. There are three:
1. Digital Voice (over broadband)
BT, Sky, Virgin and others offer Digital Voice — your existing landline number ported to a service that runs over your home broadband. Requires a stable broadband connection. Older analogue alarms and lifts often need replacement or extra adapters. Continues to use a normal-looking landline handset.
2. VoIP (cloud phone system)
A full cloud-based phone system delivered via an app. Suits businesses needing extensions, call queues, IVR menus and CRM integrations. Depends on internet quality and app behaviour. Typically £7-£20 per user per month.
3. SIM-based replacement (ONSIM)
A small ATA box plugs into your existing analogue phone. The box uses the UK mobile network — no broadband needed, no app, no engineer visit. Works with existing analogue alarms and lifts. Available to everyone, no eligibility check. £10/mo with a one-off £79 box (30-day rolling), or £18/mo with the box included (24-month contract).
Why ONSIM Landline Replacement is often the simplest answer
- Available to anyone — no vulnerability gatekeeping, no broadband test
- Keep your existing phone, alarm or lift — no new hardware to learn
- No broadband required — runs over the mobile network
- Number porting included — keep your existing landline number
- Order online, live in days — not weeks of BT case-handling
Frequently Asked Questions
The questions most people have when they've come across EVAc and want to know if it's a fit.
What is EVAc?
EVAc stands for Equivalent Voice Access Connection. It's a last-resort phone service BT provides to a small number of vulnerable residential customers who cannot migrate to a digital alternative after the PSTN switch-off in January 2027. Eligibility is narrow and availability is at BT's discretion. EVAc is not a commercial product and is not available to businesses.
Who is eligible for EVAc?
EVAc is reserved for vulnerable residential customers who (a) do not have broadband, (b) do not need or use broadband, and (c) meet BT's vulnerability criteria such as age, disability or healthcare dependency. If you have broadband on your WLR (Wholesale Line Rental), or you're a business customer of any size, you don't qualify.
Is EVAc available to businesses?
No. EVAc is a residential-only offering for vulnerable customers. Businesses of any size — sole traders, limited companies, charities, public sector — are not eligible. Businesses needing to replace a copper landline after the 2027 switch-off must use a commercial product such as Digital Voice (over broadband), VoIP, or a SIM-based landline replacement like ONSIM Landline Replacement.
Will EVAc work if I have broadband on my line?
No. EVAc is specifically for customers without broadband. If you have an active broadband service on your WLR — even a slow ADSL line, and even if you barely use it — you do not qualify for EVAc. You'll need a digital replacement, either Digital Voice over your existing broadband or a SIM-based alternative.
Is EVAc available everywhere in the UK?
Availability is at BT's discretion and is not guaranteed. The service is provided on a case-by-case basis where BT determines the customer cannot reasonably migrate to a digital alternative. Several consumer groups including Age UK and Citizens Advice have reported inconsistent application of EVAc eligibility. You cannot order EVAc the way you order a normal phone service.
What is ONSIM Landline Replacement?
ONSIM Landline Replacement is a commercial product that plugs into your existing analogue phone via a small ATA box and delivers calls over the UK mobile network — no broadband, no VoIP, no engineer visit. It is available to anyone in the UK, includes number porting, and works with alarms, lifts and other analogue devices. £10/month + £79 device (30-day rolling) or £18/month device included (24-month contract).
How do I choose between EVAc and ONSIM Landline Replacement?
EVAc is only an option if you are a vulnerable residential customer who BT determines cannot migrate digitally and who has no broadband. For everyone else — most households with broadband, all businesses, alarm and lift users, anyone with normal call patterns — ONSIM Landline Replacement is the simpler, available-everywhere option that doesn't depend on BT's discretion.
What about other PSTN replacement options?
There are three commercial routes: (1) Digital Voice — your existing landline number ported to a digital service that runs over your broadband (offered by BT, Sky, Virgin and others); (2) VoIP — a full cloud phone system through an app, suited to businesses needing extensions and call routing; (3) SIM-based replacement — ONSIM Landline Replacement for analogue hardware, or ONSIM Landline SIM for mobile-first business use. The right choice depends on whether you have broadband, whether you want to keep an existing analogue handset, and whether you need business features.
Will my existing analogue phone, alarm or lift still work?
With ONSIM Landline Replacement, yes — your existing analogue phone, alarm or lift plugs into the ONSIM box and continues working. The product is designed for exactly this use case. With Digital Voice you'll need to confirm your specific equipment is compatible — many older alarms and lifts are not. With EVAc the same caveat applies.
Can I keep my existing landline number?
Yes, on every commercial replacement route. Number porting is included with ONSIM Landline Replacement, with Digital Voice, and with most VoIP services. EVAc also keeps your existing number where it is offered. See the keep-your-landline-number guide for the porting process.