If you’ve spotted the term “carrier pre select” on a phone bill, in a cold call, or while researching cheaper business calls, here’s the direct answer: carrier pre select (CPS) is a UK telecoms facility that lets you route your outbound calls through a different provider’s network, while your phone line itself stays with your existing supplier, usually BT via Openreach. You don’t dial any extra digits and you don’t need new equipment. Your calls are simply routed automatically at the local telephone exchange to whichever provider you’ve chosen.

CPS was a big deal in the late 1990s and 2000s, when it broke BT’s monopoly on call pricing. It’s far less relevant today, mainly because most people are on inclusive call bundles, and because the whole system is being phased out as the UK’s copper phone network shuts down. Below, we’ll explain exactly how carrier pre select works, who it still matters to, and what’s replacing it.

What Is Carrier Pre Select, in Plain English?

Carrier pre select is a facility that lets you nominate, in advance, which telecoms provider carries some or all of your outgoing calls, without changing your phone line, your phone number, or how you dial. The choice is set up once at your local telephone exchange, and from then on your calls are automatically routed to your chosen provider.

This is different from simply switching phone providers entirely, which usually involves porting your number and moving your whole line to a new supplier. With carrier pre select, BT (or whoever owns your physical line) keeps billing you for line rental and any calls that fall outside your chosen categories, while your CPS provider bills you separately for the calls you’ve routed to them.

It’s also worth being clear about what carrier pre select is not. It’s not a mobile phone feature, it’s not something available on modern fibre or VoIP lines in the same form, and it’s not the same as an indirect access code, which we’ll cover below.

How Carrier Pre Select Actually Works

When carrier pre select is set up on your line, the exchange itself is configured to recognise the type of call you’re making (local, national, international, or mobile, for example) and route it to your chosen carrier’s network automatically. There’s no dialling delay, no prefix to remember, and no box to plug in.

You can typically choose to route only certain categories of calls through your CPS provider. A common setup was routing all international and mobile calls through a cheaper CPS provider while leaving local and national calls with BT, though the exact categories on offer depended on which provider you signed up with.

A handful of call types are always excluded from carrier pre select, regardless of your setup. These include:

• Emergency calls (999 and 112)
• Operator assistance and directory enquiries
• Certain unmetered internet access number ranges, specifically those starting 0844 04 and 0808 99

These always route over your existing line provider’s network and appear on that provider’s bill, not your CPS provider’s.

Carrier Pre Select vs Indirect Access: What’s the Difference?

This is where a lot of people get confused, and it’s worth being precise about it.

Carrier pre select (CPS) is automatic. Once it’s set up, your calls route through your chosen provider by default, with no action needed from you each time you pick up the phone.

Indirect access, sometimes called an override or dial-around code, requires you to manually dial a prefix (historically something like 1280, though the exact codes varied by provider) before the number you’re calling, every single time. It’s manual rather than automatic, and it’s useful if you want to use a different provider occasionally without setting up permanent CPS.

In fact, the two can work together. Even if you have CPS active for most calls, dialling the correct indirect access prefix lets you override it and route that one call over the default network instead, which is handy if you need to make a call that your CPS provider doesn’t handle well.

Who Regulates Carrier Pre Select in the UK?

Carrier pre select isn’t just a product BT chooses to offer out of goodwill. Ofcom has determined that BT holds significant market power (SMP) in various wholesale telephony markets, and as a result, BT is bound by SMP Condition AA8, which requires it to provide CPS to other communications providers on reasonable, cost-based terms.

This means any UK telecoms provider can, in principle, offer their customers CPS by arranging access through BT’s wholesale network (BT Wholesale, now part of Openreach’s commercial arm), rather than needing to build their own physical line into every customer’s home or office.

Carrier Pre Select vs Wholesale Line Rental (WLR): Not the Same Thing

You’ll often see carrier pre select mentioned alongside Wholesale Line Rental (WLR), and while the two are related, they’re not interchangeable.

WLR is where another provider takes over billing for your actual phone line rental from BT, effectively becoming your line provider even though the physical line is still BT’s. CPS, by contrast, leaves your line rental exactly where it was and only redirects specific categories of calls to another network.

A provider can offer CPS on its own, WLR on its own, or both together (sometimes called CPS with WLR), and the wholesale charges BT applies differ depending on which combination is in place.

Is Carrier Pre Select Still Available in 2026?

This is the honest, current answer most older guides on this topic don’t give you: carrier pre select is now largely legacy technology, and its relevance is shrinking fast for a specific reason.

Openreach has not accepted new orders for standard analogue phone lines since September 2023. Since CPS depends on a working PSTN (Public Switched Telephone Network) exchange connection, it can’t be newly set up on lines that no longer exist in that form. If you already have CPS active on an existing analogue line, it will generally keep working until that line is migrated, but it isn’t something you can newly order on a brand new connection today.

More significantly, the entire PSTN is being switched off. The UK’s copper landline network is scheduled for permanent retirement on 31 January 2027, having already been delayed twice from an original target of December 2025. As of May 2026, an estimated 2.4 million lines in the UK were still to migrate off the old network, with wholesale prices for remaining PSTN lines set to roughly double during 2026 as Openreach pushes the remaining customers towards digital alternatives. Once your line moves to Digital Voice or a VoIP-based service, carrier pre select in its traditional exchange-based form simply doesn’t apply anymore, since calls are routed over your broadband connection rather than the old copper switch.

Why Carrier Pre Select Mattered (and Why It Matters Less Now)

In the early 2000s, CPS was genuinely useful, because BT’s own call rates, particularly for international and mobile calls, were often far higher than what a competing CPS provider could offer over the same physical line. Switching to CPS for those call categories could meaningfully cut a household or business phone bill without any disruption.

Today, that gap has mostly closed. Most UK landline and mobile tariffs now include generous, or entirely unlimited, inclusive minutes as standard, which removes much of the original financial incentive to shop around for a separate carrier just for certain call types. CPS still shows up occasionally in the business telecoms world, particularly for organisations running older multi-line systems, PBX setups, or legacy alarm lines where switching providers entirely would be disruptive, but for most residential customers it’s simply not something you’ll encounter or need to set up in 2026.

Watch Out: CPS-Related Cold Calls and Mis-Selling

This is a genuine consumer protection issue worth flagging, since it doesn’t get covered well elsewhere. Because CPS can be set up on your line without you physically doing anything at your property, it has historically been used as a vehicle for mis-selling, sometimes called “slamming”, where a caller convinces you (or someone in your household) to agree to a switch you didn’t properly understand or consent to.

If you receive a cold call claiming your line will be “cut off” unless you agree to a change, or offering to “save you money” by switching your carrier there and then over the phone, treat it with real caution. Genuine providers won’t threaten disconnection to force a same-call decision. Ofcom’s rules require your consent to be properly informed before any switch takes place, and if you believe you’ve been mis-sold or switched without proper consent, you can raise a complaint with your provider first, then escalate to the Communications Ombudsman or Ombudsman Services: Communications if it isn’t resolved within eight weeks.

How to Set Up, Check, or Cancel Carrier Pre Select

If you want to check whether CPS is currently active on your line, or set it up, cancel it, or query a change you didn’t request, contact your current phone provider directly rather than a third party who cold-calls you about it. Ask them explicitly to confirm your current carrier selection status in writing.

To cancel CPS and revert to your default provider for all calls, you generally just need to contact either your CPS provider or your line provider (BT, in most cases) and request the change. There’s typically no cost to remove it, though it’s sensible to check your contract terms first in case a minimum term applies with your CPS provider specifically.

What’s Replacing Carrier Pre Select

As the PSTN switch-off completes, the concept CPS was built around, choosing a different network operator for specific call types over a shared copper line, doesn’t really exist in the same way on VoIP and full fibre connections. Instead, competition happens at a different level: you simply choose your broadband and phone provider outright, and switching between VoIP providers (rather than selecting a secondary carrier on top of your existing one) is now the main way UK consumers and businesses shop around for better call rates.

For businesses still relying on older systems, the practical move is usually to a hosted VoIP or cloud phone system ahead of the January 2027 deadline, rather than trying to preserve a CPS arrangement that Openreach is actively retiring.

FAQs

What does carrier pre select mean?

Carrier pre select (CPS) means your phone line automatically routes certain types of outgoing calls, such as international or mobile calls, through a different provider’s network than the one that supplies your physical line, without you needing to dial any extra digits.

Is carrier pre select the same as changing phone provider?

No. Changing provider usually means your whole line, billing, and sometimes phone number move to a new supplier. Carrier pre select only redirects specific categories of calls to another provider while your original line and its provider stay exactly as they were.

Do I need to dial a code to use carrier pre select?

No, that’s the main point of it. CPS routes eligible calls automatically once it’s set up. Dialling a prefix code before a number, such as the old 1280 style codes, is a separate method called indirect access, and it’s manual rather than automatic.

Can I still order carrier pre select in 2026?

Not on a new line. Openreach stopped accepting orders for new standard analogue phone lines in September 2023, and since CPS depends on that copper exchange infrastructure, it can’t be newly set up going forward. Existing CPS arrangements on older lines will keep working until those lines migrate to digital services.

Will carrier pre select still work after the PSTN switch-off?

No. Once your line moves to Digital Voice or another VoIP-based service ahead of the 31 January 2027 switch-off deadline, calls are routed over your broadband connection rather than the old copper exchange, and traditional carrier pre select no longer applies in its original form.

Does carrier pre select cost anything to set up?

For most residential customers historically, there was no direct charge to select a CPS provider, though the CPS provider itself typically charged its own rates for the calls it carried. Business orders sometimes involved a small setup charge from BT, so it’s worth checking directly with your chosen provider.

Why did I get a call about switching my carrier pre select?

Cold calls offering to switch your carrier pre select were a known route for mis-selling in the past, sometimes pressuring people into agreeing without proper understanding. If you get a call like this, don’t agree on the spot. Contact your existing provider directly to verify any claims before making a decision.

What’s the difference between CPS and Wholesale Line Rental?

CPS only redirects specific call types to another provider while your line rental billing stays where it was. Wholesale Line Rental (WLR) is different: it’s where another provider takes over the billing for your actual line rental itself, even though BT’s physical infrastructure remains underneath.