Cold calling vs cold emailing: why my prospects prefer to call

Cold calling vs cold emailing usually comes up as an either-or: pick up the phone, or write. In the campaigns I run, the answer turned out to be both, in an order I had not planned. The emails go out cold, and the prospects make the call.

Cold calling means phoning a business that has not asked to hear from you, to offer it something. Cold emailing means sending a short, personal email to a business contact who has not heard of you. Both are ways to win B2B clients, and both are allowed in the UK and in France, under rules that differ from one channel to the other.

I run cold email campaigns, not call campaigns, so I am not neutral. This comparison covers what each channel does well, where each one struggles, the rules in both countries, and how I write emails that make the phone ring. It is part of my B2B cold emailing guide, which covers the whole process.

Cold calling vs cold emailing at a glance

Side by side, on the points that decide most choices:

The 30-a-day figure is what Instantly’s own guides suggest for one mailbox; for more volume, you add mailboxes instead of pushing each one harder. Neither column wins on every line, so the real question is which channel to start with, and how to make the two work together.

Cold calling: a live conversation, one call at a time

Cold calling’s strength is the conversation. When the right person picks up, you hear their objection and answer it on the spot, and within a minute you know whether there is any interest, and if not, why. A morning on the phone also tells you how your offer sounds to the people you want to sell to, sooner than any email test would.

It suits a short list of valuable accounts, where every conversation counts, and offers that need explaining before anyone will consider them. It also needs no infrastructure: a phone and the right numbers are enough to start.

Its limits come from the same place:

• It interrupts. You call when it suits you, not them, and a busy owner in a meeting or on a site visit will not pick up, or will pick up distracted.
• You often reach the wrong person. The number you can find is usually a switchboard, a reception desk or a voicemail.
• It runs one conversation at a time. Even with a dialler, one person talks to one prospect at a time, so the hours in the day cap the volume.
• It wears people down. A day of refusals takes a thick skin, and few people keep it up for weeks on end.
• In the UK, it needs screening. Numbers go through the TPS and CTPS registers before you dial (more on that below).

Cold emailing: many prospects at once, answered when they choose

Cold emailing turns the timing round: the prospect reads your message when it suits them. Sending runs in parallel across several mailboxes, so a small team can write to hundreds of the right businesses a month without spending its days on the phone.

It is also the channel you can improve by testing. I A/B test the emails, and responses usually grow over time, because I learn which copy works and which does not. On my campaigns, the first result comes within 36 hours of the first send.

Its limits are real too:

• The set-up takes weeks. You need secondary domains, mailboxes and a sending tool, and new mailboxes go through a few weeks of warm-up before they send at full volume.
• It is easy to ignore. Deleting an email takes a second.
• Writing back is work. A written answer waits for a quiet moment at a desk, and busy people rarely have one.
• It is a B2B channel. In both countries, consumers cannot be cold emailed without their consent, and in the UK neither can sole traders.

That third point is the one that shaped my campaigns.

Why the prospects I email prefer to call

For Pilotech, an air conditioning installer near Paris, my cold email campaigns target three audiences: Paris restaurants, Paris offices and shops, and architects, who are the main focus. Each contact receives three plain-text emails at most. The first is three lines long, invites the reader to call the number written in the email and to look at the catalogue on the website, and contains no link. The emails are signed by the founder, with his phone number. Over a year, the campaigns brought Pilotech 15 new clients.

The surprise was how people answered. Many prospects, architects most of all, did not reply: they called. My reading of why:

• A call is faster. People do not have time, so they call the moment they have one, while a written reply has to wait.
• Emails get buried. A reply put off until later sinks under the rest of the inbox.
• A call is like ticking off a to-do list. One call and the matter is dealt with, with no thread to follow.
• People like real human contact. Talking to the person behind the offer feels more natural than writing to a stranger.

I did not fight it: I made calling even easier in the sequences. Written replies keep going to the founder, who answers them himself, since I do everything in a campaign except the replies.

So here is my answer to cold calling vs cold emailing. Let the email do the cold part, and let the prospect make the call. Whoever rings has read your offer and chosen to talk about it, at a moment that suits them, so the conversation starts warm. The full story, with the set-up of the campaign, is in my cold email case study.

The rules for cold calls and cold emails in the UK and France

In the UK

Calls fall under regulation 21 of PECR, the Privacy and Electronic Communications Regulations. You may make live sales calls to businesses without their consent, on three conditions:

1. Do not call a number registered with the Telephone Preference Service (TPS), the register for individuals, which is also where sole traders sign up, or with the Corporate TPS (CTPS), the register for companies, unless that person or business has told you specifically that they are happy to take your calls.
2. Screen against your own do-not-call list as well, so that nobody who said no hears from you again.
3. Say who is calling, and display a number they can call back.

The ICO’s guidance on telephone marketing sets out the detail.

Emails fall under regulation 22. You can email limited companies and LLPs without consent, but sole traders and partnerships outside Scotland count as individuals, so they must have agreed first. Every email names the sender and gives a way to opt out, and UK GDPR still applies to a named work address. My cold email GDPR checklist goes through it step by step, for both countries.

In France

The CNIL allows phone prospecting of professionals when the call concerns their work; its own example is software offered to a company’s IT director. The person must have been told their number could be used for prospecting and be able to object simply and free of charge, including when you got their details from a third party. On the call, say who you are and remind the person they can refuse further calls; if they do, add them to your do-not-call list. The CNIL’s page on phone prospecting (in French) has the detail.

The rules for calls to consumers have changed. Since 11 August 2026, a business may no longer phone a consumer to sell them something without their prior consent, under loi n° 2025-594 of 30 June 2025, as the DGCCRF explains (in French). The rule protects consumers: an architect called about a project stays under the CNIL’s rules for professionals.

Emails follow the same logic as calls to professionals: no prior consent when the message relates to the recipient’s job, as long as they were told and can object, and every email names the sender and offers a simple way to unsubscribe.

How to make the email bring the call

The hybrid only works if calling is easy and someone answers. The first four steps are how I write the emails; the last three are for whoever takes the calls.

1. Write the number in the email. In full, in the body and under the name, with a plain invitation to call. No link and no HTML: I send plain text only, because it protects delivery.
2. Sign with the name of the person who answers. Pilotech’s emails are signed by the founder, with his own number, so a prospect who calls reaches the person named in the email, not a switchboard.
3. Keep the first email to three lines: who you are, the offer, the invitation to call. Name the page of your website to look at rather than linking to it. My cold email examples show complete first emails built this way.
4. Stop at three emails. The third still brings positive replies, from people who had simply been too busy to answer the first two. My guide to cold email follow-ups explains why I stop there.
5. Decide who picks up, and when. Set the hours when the line is answered, record a voicemail greeting that names your company, and call back the same day. MLK Leadhunters’ article on what to do with replies recommends answering within the hour; a missed call deserves the same speed.
6. Log every call and set call-back reminders. For Pilotech, the websites, SEO and cold emails together now bring about ten prospects a day. At one point there were more than the team could follow, and the founder asked me to build an internal app so that no call-back is missed. You can start smaller: my tutorial to automate lead follow-up sets up free alerts and call-back reminders with Google Apps Script.
7. Count the calls as results. A sending tool counts written replies; it cannot hear the phone ring. Ask whoever answers to note where each call came from. My own guarantee works the same way: if no lead has replied or called, I add an extra month of campaign for free.

Which one should you choose?

Choose the channel that fits your list and your time, not the one that sounds more modern.

Start with cold calling if you have a short list of valuable accounts, someone on your team enjoys the phone and takes a refusal in their stride, and your offer needs a conversation before it makes sense. You do not need me, or any tool, for that: screen the numbers if you are in the UK, block an afternoon, and call.

Start with cold emailing if you can list your buyers by the hundred, your days are too full to spend on the phone, and you want to test offers before you commit to one. Allow a few weeks for the set-up. I will admit my bias here: for a business that sells to other businesses, I think cold emailing is the one channel that can take you to the moon, and your competitors will do it anyway.

Combine them if someone can answer the phone during working hours. Let the emails bring the calls. If you also want to phone the people who did not respond, remember that those are cold calls, with the screening and opt-out rules above.

If you are weighing paid ads as well, my comparison of PPC vs cold email covers that choice.

A small campaign is within reach of any small team: two mailboxes, a sending tool and a verified list of a few hundred businesses. If you would rather hand over everything except the conversations, that is how MLK Leadhunters works: the studio’s cold email practice finds the leads, writes and sends the emails, and leaves the replies and the calls to you.