- Only about a quarter of people say they'd pick up a call from a UK mobile they don't recognise. A text saying who will call, sent first, is what gets the call answered.
- Use AI for the first reply, simple questions and booking. Hand over to a person fast, and always when someone asks.
- WhatsApp needs opt-in that names your business, and you can only start a conversation with an approved template.
- An AI voice calling people is an automated call in the UK and an artificial voice in the US. Both need specific consent before you use one for marketing.
- Speed opens the door. A person who calls within minutes, with the right price, still wins the sale.
- WhatsApp in the UK, text in the US: nine in ten UK online adults use WhatsApp, a third of US adults do.
The short answer
The fastest follow-up is a message in seconds that says who will call, then a person calling within minutes. AI makes the first part easy at any hour. It doesn't replace the call. And people screen unknown numbers more than ever, so the message before the call matters as much as the call itself.
What the first minutes should look like
The study behind the five-minute rule tracked over 15,000 leads at six companies. The odds of qualifying a lead fell four times between 5 and 10 minutes. It's old and was run with a sales software firm, so treat the exact numbers with care. The direction has never been in doubt.
- Quote request sentThey've just filled in the form, phone in hand.
- Text from the businessHi Jo, it's Sam from [your business]. I'll call you in the next few minutes from 01632 960123.
- Incoming call: [your business]They know the name and the number, so they answer.
- Survey bookedA day and time agreed, confirmed by text.
Where AI helps, and where it doesn't
AI is good at the fast, repetitive part: replying the second a form arrives, answering simple questions at 10pm, offering a time for a call. It's poor at what wins the job: reading doubt, handling price, and building enough trust to let a stranger into the house for a survey.
- The first reply, in seconds, saying who will call
- Answers to simple questions: area, timing, what happens next
- Offering call or survey times
- Reminders and "we tried to call" messages
- The first real conversation
- Price, finance and objections
- Anyone upset, confused or asking for a person
- Anything that sounds like a complaint or a vulnerable customer
WhatsApp or text? It depends on the country
In the UK, nine in ten online adults use WhatsApp, so a WhatsApp message is often read first. In the US, only a third of adults use it at all, and a plain text reaches almost everyone. Same idea, different channel.
So we follow up by WhatsApp and text in the UK, and by text in the US. One exception worth testing in the US: over half of Hispanic adults use WhatsApp, so a Spanish-language campaign may do better there.
- WhatsApp first, a text as back-up
- Opt-in that names the business
- Open with an approved template
- Then 24 hours to chat freely
- A text first
- Consent that names your company and covers texts
- Opt-out shown in every text
- WhatsApp only where your audience uses it
WhatsApp: the rules that matter
Nine in ten UK online adults use WhatsApp, so it's tempting. The Business Platform has firm rules. You need opt-in that names your business. You can only start a conversation with a template Meta has approved. Once the person replies, you have 24 hours to message freely, and automation must offer a quick way to reach a person.
- Approved templates only
- Templates are reviewed and can be paused or rejected
- Opt-in must name your business
- Treat a marketing message like a marketing text: get consent first
- Free-form replies, including automated ones
- Each new message from them restarts the 24 hours
- A clear, direct way to reach a person
- Stop messaging the moment they opt out
What it looks like done right
Here's a WhatsApp first reply that follows those rules: an opt-in that names the business, a template to open the chat, an assistant that says it's automated and sticks to the request, and a person who takes the call.
- 1The adA plain offer in the firm's own name.
Your Heating CoOld boiler playing up? Get a quote in 60 seconds
- 2The pageThe opt-in names the business and the channel.Your Heating CoA new boiler for your Leeds home?Question 1 of 4
What do you need?
A new boilerA repairNot sureNext - 3WhatsAppIt says it's automated, asks two questions, and books a call with a person.YYour Heating Coonline
New enquiry, 12:01
AI assistantHi Jo, this is Your Heating Co's automated assistant. Thanks for your boiler quote request. Two quick questions so Sam can call with the right answers?
Sure, but I'm at work
AI assistantNo problem. Is it a combi boiler, and roughly how old?
Combi, about 15 years
AI assistantThanks. Sam can call today at 5:30pm or tomorrow at 9am. Or reply PERSON to talk to someone now.
5:30 is fine
Call booked for 5:30pm. Sam takes over from here.
Only with an opt-in that names your business. The first message is an approved template; free replies are allowed for 24 hours after the person's last message. The assistant says it's automated, stays on their request, offers a person at any time and stops when asked.
AI voice agents: UK and US rules
An AI voice that calls people isn't a live call in the eyes of either regulator. In the UK, a marketing call that plays anything other than live speech is an automated call: the ICO says even an AI greeting needs specific consent. In the US, the FCC ruled in February 2024 that AI voices are artificial voices.
- Consent specifically for automated calls, from you
- Consent to live calls isn't enough
- Say who you are and give an address or freephone number
- Show a number they can call back
- Prior express written consent for telemarketing to mobiles
- Name the business at the start of the call
- A key-press or voice opt-out within two seconds of that
- Only between 8am and 9pm their local time
What we do
We follow up by WhatsApp and text in the UK, and by text in the US. The first message goes within a minute in the business's name, saying who will call and from which number. Texts go between 9am and 8pm, Monday to Saturday; outside those hours an email goes at once and the text waits until 9am.
What we'd do
If you're setting up follow-up for bought or own leads this year, this is the order we'd build it in.
- 1Send one message in a minute
Your name, your business and when you'll call. Keep it about their request: one offer turns it into marketing that needs consent.
- 2Call within five minutes
A person, in working hours. Then again in an hour and early evening, and about six tries over five days.
- 3Let AI cover the gaps
Evenings and weekends: answer simple questions and book a call for the morning. Hand over the moment someone asks for a person.
- 4Add WhatsApp only with opt-in
A tick that names your business and the channel, approved templates, and a fast route to a person.
- 5Never automate these
AI voice calls without consent for automated calls, pretending a bot is a person, chasing after a stop, or price talks.
AI prompts to set up your follow-up
Copy these into ChatGPT or Claude and fill in the brackets with your own details. Test anything automated on yourself and your team before a customer sees it.
Write my first-minute messageThe text that goes out within a minute and gets your call answered.
You are a customer service lead for a UK [trade] firm. Write the first message [company] sends within a minute of a new quote request, so the person answers when we call.
About us: we cover [area], we call from [number], the person who calls is usually [name], and we text between [hours and days].
Write:
1. A text for working hours: their first name, my name and company, that I'll call in the next few minutes, and the number I'll call from. Under 160 characters.
2. A text and an email for requests outside our texting hours: we've got it, and when exactly we'll call.
3. A version to submit to Meta as a WhatsApp template, with the variables marked like {{1}}, for people who ticked a WhatsApp opt-in that names us.
4. A "sorry we missed you" text for after a missed first call.
Rules: keep every message about their request. No offers, discounts or links to deals (one offer turns it into marketing that needs consent). No fake urgency. Plain UK English.Write the instructions for my AI assistantA ready-to-paste brief for an AI that answers texts or WhatsApp.
You are setting up an AI assistant that replies to new enquiries for [company], a [trade] firm in [area], by [text / WhatsApp]. Write the full instructions I'll give the assistant. It must: - say in its first message that it's an automated assistant for [company], - answer only these questions: [areas covered, how long a survey takes, what happens next, opening hours], - ask at most [number] short questions: [e.g. home owner? what they need? best time to call?], - offer a call or survey from these slots: [slots], - hand over to a person straight away when someone asks for one, is upset or confused, mentions price or finance, sounds like a complaint, or may be a vulnerable customer, - stop messaging at once if they say stop, and confirm it has stopped. It must never: pretend to be a person, quote prices, promise savings or grants, give advice on finance, or message anyone who hasn't opted in. Then write 10 test conversations to run before going live, including: "are you a real person?", "how much?", "stop", someone angry about a past job, and someone who seems confused. Show the reply you'd expect for each. This is not legal advice: check the setup with a compliance adviser before you switch it on.
Check my consent wordingPaste your form's wording and see what it covers.
You are a careful reviewer of UK marketing consent wording (PECR and UK GDPR). Here is the consent wording and tick boxes on our quote form, and the page it sits on: [paste wording and page URL or text]. We want to contact people by: [calls / texts / email / WhatsApp / automated or AI calls]. Our business name is [company], and [we are the only firm who will contact them / a partner will also contact them: name]. Tell me, for each channel: 1. Whether the wording clearly covers it, and why or why not. 2. Whether it names the business that will make contact. 3. What's missing or vague (e.g. "selected partners", no mention of automated calls). Then suggest clearer wording, as separate optional ticks where a channel needs its own consent, and list what we should store with each consent (time, page, wording version). This is not legal advice. Flag anything I should check with a compliance adviser.
Map what to automate and what to keep humanYour follow-up, step by step, split between AI and your team.
You are an operations adviser for a UK [trade] firm. Here's how we follow up new enquiries today: [describe every step, who does it, and when]. We get about [number] leads a week, and [number] people can call. Our hours are [hours]. Produce a table with every step, and for each one: "let AI do it", "keep a person" or "never automate", with a one-line reason. Use these rules: - AI can send the first reply, answer simple questions, offer call times and send reminders. - A person handles the first real conversation, price, finance, objections, anyone upset or asking for a person, complaints and vulnerable customers. - Never: AI voice calls without consent for automated calls, a bot pretending to be a person, messaging after someone says stop. Then tell me the three changes that would cut our time to first contact the most, in order, and what each needs (tools, consent, people).
Review an AI conversationPaste a chat your assistant had and get it marked.
Here is a conversation between our AI assistant and someone who asked [company] for a quote: [paste]. Mark it, in short points: 1. Did it say it was automated in the first message? 2. Did it stay on their request, with no offers or pressure? 3. Did it hand over to a person at the right moment, or too late? 4. Did it say anything that could read as a promise (price, savings, dates, grants)? 5. Did it stop when asked? Then rewrite any weak replies, and suggest one change to the assistant's instructions so it doesn't happen again.
What this page is
General information about UK and US rules as we read them on 9 November 2026, not legal advice. Platform policies change often. Check with a compliance adviser before you switch on automated messages or AI calls, and use only consent that covers the channel you're using.
Common questions
Can I use an AI voice to call leads in the UK?
Only with consent given specifically for automated calls from you. The ICO treats any recorded or AI-generated speech in a marketing call as an automated call, and consent to live calls doesn't cover it.
Can I message a new lead on WhatsApp?
Only if they've opted in to messages from your business, and only with an approved template to start the conversation. Once they reply, you can message freely for 24 hours.
How fast should I reply to a new lead?
A message within a minute saying who will call, and a call from a person within five minutes in working hours. Evening leads get the message straight away and a call first thing.
Will AI replace my sales team?
No. It's good at the first reply, simple questions and booking. People still buy home improvements, insurance and legal help after talking to a person they trust.
Sources
- Ofcom: Cracking down on scam calls from abroad, 21 July 2025 (research from February 2025)
- Ofcom: From apps to AI search, how the UK goes online in 2025 (Online Nation), 10 December 2025
- Lead Response Management study (Oldroyd with InsideSales.com, 2007)
- WhatsApp Business Messaging Policy (updated 23 September 2026)
- Meta for Developers: getting opt-in for WhatsApp
- Meta for Developers: WhatsApp message templates
- PECR 2003, regulation 19: automated calling systems
- ICO: Telephone marketing
- ICO innovation advice: previously asked questions (AI-generated greeting in marketing calls)
- ICO: Identify direct marketing
- FCC: FCC makes AI-generated voices in robocalls illegal, 8 February 2024
- 47 CFR 64.1200: delivery restrictions (identification, opt-out, calling hours)
- Pew Research Center: Americans' use of social media, 2026
Tell us your area and the hours your team can pick up the phone. We'll price leads or live transfers around when you can call them.
Written by Sofia Abrantes, Co-founder and COO at Convrsion. Prices and figures come from the sources listed and were checked on 9 Nov 2026. Convrsion runs lead generation campaigns in the UK and US, so we buy, sell and follow up leads every day; this page is general information, not a quote or legal advice.
