O2 Call Divert: A Complete How-To Guide for 2026

O2 call divert sends your incoming calls to another UK fixed line or mobile number instead of letting them ring on your handset. You can set it up with O2 network codes or through your phone's call-forwarding settings, and you can divert all calls or only the ones you miss, can't answer, or receive while busy.

If you're on a job, in the van, with a client, or just tired of hearing that you missed another lead while your phone was in your pocket, this is one of those small features that can make a real difference. It's basic on the surface, but in practice it affects bookings, response times, and whether a caller gets a person, a voicemail, or nothing useful at all.

What Is O2 Call Divert and Why Use It

A customer calls while you are on-site, driving between jobs, or already speaking to someone else. If nobody picks up, that caller often moves on fast.

O2 call divert is a network feature that sends incoming calls to another UK number. You can forward calls to a second mobile, a landline, or a shared business line so someone else has a chance to answer.

For a small business owner, that solves a real problem. Calls rarely arrive at a convenient moment. They come in while you are with a customer, quoting, loading the van, or trying to finish the admin you already put off twice. Diverting calls gives you basic cover when one handset cannot do everything.

Why it's useful in day-to-day work

Call divert makes sense in a few common situations:

• You're away from your main phone: Send calls to a colleague or backup handset.
• You spend time on jobs or on the road: Let calls continue to a number that still gets monitored.
• You need temporary cover: Route calls elsewhere during holidays, staff sickness, or busy periods.

The practical benefit is simple. Fewer callers hit a dead end.

But there is a trade-off. A divert only changes where the phone rings. It does not improve how calls are handled after that. If you forward to another mobile and that person is busy too, the caller still waits, still misses help, or still hangs up.

That is the gap many business owners notice after the first setup. Forwarding helps with availability. It does not create a call-handling process.

That is why it helps to look beyond simple forwarding and understand how call routing works for business call handling. A routed setup can send callers to the right person, use fallback paths when nobody is free, and avoid the common problem of diverting one unanswered call to another unanswered line.

How Do I Set Up Call Divert on O2

You are halfway through a job, the phone keeps ringing, and you need calls to go somewhere useful now. On O2, the quickest setup is usually done through network codes entered in your phone dialler.

For diverting all calls, use \*\*21\*target#. Replace target with the full number you want calls sent to, then press call. If O2 accepts the request, you should see a confirmation on screen.

When unconditional divert makes sense

An all-calls divert is best for short periods when one person or one number needs to take everything.

Typical examples include:

1. You have one person covering calls for the day 2. You are switching to a different work mobile temporarily 3. You want the office or receptionist line to handle every incoming call

It is quick to turn on, but the trade-off is clear. Your O2 mobile stops ringing for incoming calls while the divert is active. For a small business, that works if the destination number is being answered. If it is another busy mobile, the problem has only moved.

O2 call divert codes at a glance

A few checks save hassle later.

• Enter the full destination number carefully. One wrong digit can send calls to the wrong place or stop the divert from working.
• Use a number your business monitors. A divert only helps if someone, or something, answers at the other end.
• Test it straight away from another phone. Do not assume it worked because the code looked right.

Step-by-step setup on O2

1. Open your phone app. 2. Tap the keypad or dialler. 3. Enter the code for the divert type you want. 4. Add the destination number straight after the code. 5. End the entry with #. 6. Press call. 7. Wait for the network confirmation message.

That is the mechanical setup. The business question comes next. Where do those calls land, and what happens if that line is already tied up?

Many owners start with a simple divert, then realise they still have missed calls because the backup mobile is on another job, in poor signal, or already handling someone else. If you want a clearer view of the options, this guide to business call divert setups and their limits explains where basic forwarding helps and where it falls short.

For day-to-day operations, that distinction matters. Diverting a call is not the same as handling a call.

How to Use Conditional Diverts and Cancel Them

Conditional diverts suit day-to-day business use because they only step in when your phone cannot take the call. That gives you a simple way to catch overflow without sending every caller somewhere else from the start.

Which conditional divert should you use

Each option solves a different problem:

• Busy: Use \*\*67\*target# to divert calls only when you are already on another call.
• No reply: Use \*\*61\*target# to let the phone ring first, then send the call elsewhere if you do not answer.
• Unreachable: Use \*\*62\*target# to divert calls when your phone is switched off or out of signal.

For many sole traders, the best starting point is no reply. It still gives you the chance to answer directly, which matters for regular clients and urgent jobs, but it stops the call from dying if you are driving, with a customer, or away from the phone for a minute.

You can also set a delay for no-reply divert with \*\*61\*target\*11\*seconds#. A common setup is 15 seconds, but the right timing depends on how you work. Too short, and calls divert before you have a fair chance to answer. Too long, and callers may hang up before the transfer happens.

That timing choice is a business decision, not just a phone setting.

A quick way to choose is to match the rule to the failure point in your day:

• Busy divert fits owners who spend long stretches on client calls.
• No-answer divert fits businesses that want to answer personally when possible.
• Unreachable divert fits field-based work where signal drops, flat batteries, and patchy coverage are part of the week.

The catch is what happens after the divert. If calls go to another mobile that is also busy, unattended, or out of coverage, the caller still gets no help. The line moved, but the process did not improve. That is why simple forwarding often stops being enough once call volumes rise or staff are often on the move.

How to cancel all O2 diverts

Use ##002# to remove all active diverts at once.

That reset is useful after testing different rules, or when calls are still forwarding and you are not sure which condition is active. Dial the code, press call, then wait for the network confirmation before testing again from another phone.

If you are comparing how UK networks handle the same forwarding logic, this guide to EE call divert settings for business users shows that the codes may vary less than the operational problem. Diverting a call is easy. Making sure someone answers it is the harder part.

That is where many small businesses outgrow basic divert rules. A service like fonea gives diverted calls somewhere reliable to land, with an AI receptionist that answers, qualifies, and routes calls instead of passing them to yet another busy phone.

Diverting O2 Calls via Your Phone Settings

If you don't like entering codes manually, your handset may let you manage forwarding through settings. In many cases that's just a friendlier front end for the same network function.

iPhone

On iPhone, the usual path is:

• Open Settings
• Tap Phone
• Tap Call Forwarding
• Turn it on
• Enter the number you want calls sent to

That menu is generally the easiest option for all-calls forwarding. If you need more specific behaviour, such as busy or unanswered-only rules, the network code method is often more flexible.

Android

Android is less consistent because the wording varies by manufacturer and software version. In most cases, you'll follow a path similar to this:

1. Open the Phone app. 2. Tap the menu or settings area. 3. Look for Calling accounts, Supplementary services, or Call forwarding [VERIFY]. 4. Choose the forwarding type. 5. Enter the destination number and save.

A few practical realities apply:

• Menu names vary: Samsung, Google, and other Android devices don't always label the setting the same way.
• Carrier support can affect what you see: Some phones show all forwarding types, others only the simplest option.
• Testing still matters: A saved setting isn't proof that the network accepted it properly.

The phone menu is easier for most people. The dial code method is usually easier to troubleshoot.

If your phone settings seem to disagree with the actual behaviour of incoming calls, trust the live test, not the screen. Ring your O2 number from another phone and confirm what really happens.

O2 Call Divert Not Working? Common Fixes

You switch on call divert because you cannot pick up, then a customer says the call never reached the backup number. In practice, the problem is usually simple. The network did not accept the code, the destination number was entered incorrectly, or voicemail and existing divert rules are clashing.

Start with a live test. Call your O2 number from another phone and watch what happens. A saved setting on the handset is helpful, but the actual result matters more than what the screen says.

Check the obvious causes first

Work through these in order:

• Re-enter the code carefully: One missing *, #, or digit can stop the divert from being applied.
• Check the destination number: Use the full UK number and confirm it is the exact line you want calls sent to.
• Clear old rules: Dial ##002# to cancel all diverts, then set up only the one you need.
• Avoid mixing methods during testing: If you changed settings in your phone menu and by dial code, reset everything and use one method at a time.
• Restart the phone: This can clear temporary handset or network issues after a change.
• Test again from a different phone: Do not assume the change worked until you see the call route properly.

Voicemail often causes the confusion

Many O2 users presume call divert is faulty when the underlying cause is voicemail behaviour changing in the background.

Cancelling diverts with ##002# can also affect voicemail settings. That matters because a business owner may expect missed calls to fall through to voicemail, only to find that callers now hear ringing and get nothing useful at the end. If voicemail stops picking up when it should, call 1750 to turn it back on, then test again.

A clean recovery process usually works:

1. Cancel all diverts with ##002#. 2. Reapply only the divert rule you want. 3. Call your O2 number from another phone. 4. Let the call ring long enough to check the full path. 5. If voicemail no longer answers as expected, call 1750. 6. Test once more.

If voicemail is part of your backup plan, it helps to understand how O2 handles missed calls and message routing. This guide to O2 voicemail settings and behaviour covers that side in more detail.

One practical point often gets missed. A divert that sends calls to another mobile is only useful if someone is free to answer that second phone. If that line is busy, unattended, or also set to divert somewhere else, the caller is still stuck in a weak process. That is why call divert is only the first fix. The important question is what happens after the call leaves your O2 number.

Beyond Divert How to Ensure Every Call Gets Answered

Basic call divert solves one problem. It moves the call.

It doesn't solve the next problem, which is whether anyone answers at the other end. If you divert your O2 mobile to another mobile that's also in a pocket, on another job, or already busy, you've just moved the bottleneck.

For small and medium-sized businesses, that's where call handling becomes an operations decision, not just a phone setting. A good setup should answer callers in any language they use, collect the key details, book or route when appropriate, and only pass through the calls that require human intervention.

That's where AI is now useful in a practical way. You don't need to replace your team. You start by covering overflow, missed calls, after-hours enquiries, and repetitive questions that don't need a person every time. Done properly, AI supports customer service, complements humans, and gives busy teams breathing room instead of creating another system to manage.

Diverting calls only helps if they're answered at the other end. An AI receptionist like fonea answers every diverted call live, 24/7, instead of bouncing to voicemail, set up in hours. You can review pricing when you want to see whether that's a better fit than forwarding calls between mobiles.

O2 Call Divert Frequently Asked Questions

Does O2 charge for call divert

Yes. O2 typically charges diverted calls as if you placed an outgoing call to the number you forwarded to, and those calls are generally not taken from your inclusive monthly minutes.

For a business, that matters more than many owners expect. A simple divert can turn into a regular operating cost if calls are being forwarded all day to another mobile, a landline, or an out-of-hours answer point. Check your tariff and watch your usage if you plan to rely on divert frequently.

Will the caller know their call has been diverted

Usually, no. The caller will normally just hear ringing and then speak to whoever answers at the destination number.

From a customer service point of view, the bigger issue is not whether they know the call was diverted. It is whether they reach someone who can help them. If the diverted call lands on another busy phone, the customer still gets delay, voicemail, or no answer.

Can I divert O2 calls to a landline

Yes. O2 supports diverting incoming calls to a UK landline or mobile number.

That gives small businesses a practical fallback if calls need to reach an office desk, home office, or shared reception line. The trade-off is simple. A landline only helps if someone is there to answer it.

Is it better to divert all calls or only unanswered calls

For most small businesses, diverting only unanswered calls is the better starting point. You still get the chance to answer directly, and overflow is covered when you are tied up, driving, or with a customer.

Divert all calls only if you want another person or service to handle everything for a defined period, such as annual leave, site visits, or after hours.

If missed calls are costing you work, basic forwarding only solves part of the process. fonea answers diverted calls live, handles routine questions, captures caller details, and gives you a better end point than sending customers from one unanswered number to another.