One WhatsApp number, or one per person

Every WhatsApp feature a builder is shown rests on a decision that is almost never discussed in the room: does the message leave from the company, or from a person?

Templates, buttons, delivery reports and reply handling all follow from that answer, and getting it wrong costs relationships that took years to build. It belongs on the list when choosing construction software, not settled by whichever option the vendor happens to have built.

The single company number#

All outbound traffic leaves from one business number. Everyone who deals with you sees the same identity.

What that buys you:

• Continuity that survives people. The number belongs to the organisation. Staff change; the thread does not.
• A record by default. Sent, delivered, read and kept, on the company's side of the line, without asking anybody to cooperate.
• One place to change things. A template edited once changes every message that follows it. One switch turns a category of traffic off.
• A clean ending. Somebody who has left cannot keep talking to your vendors as though they still work here.

What it costs:

• Replies land in one inbox, and somebody must route them. If nobody owns that inbox, replies disappear into it, which is worse than never inviting one.
• Personal continuity is lost. The vendor who has dealt with the same purchase officer for years now hears from a company, and replies to a number that does not know him.
• Tone flattens. A statement from a company number reads as a statement. The same words from the man he has been arguing with about rates read as a nudge between two people.

One number per person#

Each person sends from the working identity the other side already has in their phone. The vendor sees a name he recognises.

The gains are the mirror image. A reply reaches somebody who knows the history. The recipient can ring the same number and get a human. The tone matches the relationship, so a chase lands as a chase and not as a form letter. Nothing has to be routed by anybody.

The costs are real and they are usually discovered late.

• The organisation's conversation lives on personal handsets. When the person leaves, so does the thread, and with it the reason a rate was agreed.
• There is no record unless one is deliberately kept, and "deliberately kept" means somebody designed for it before the first message went out.
• Work and home share a screen. A supplier messages at eleven at night about a lorry, and the family group is two swipes away.
• Nobody can cover. On a day of leave, the vendor's message sits unread on a phone in a drawer, and the sender has no way of knowing.
• The number is portable. A relationship held entirely in one person's handset can be hired away.

Which traffic belongs to which#

The mistake is not choosing the wrong model. It is choosing one model for everything.

A company identity should carry the traffic that is periodic, identical in shape, or generated by the system: a price revision, a site closure, a holiday notice, statements and ledgers, an approval waiting, a document ready, a payment released. None of these need a person present, and all of them benefit from being uniform.

The risk on this side is volume. A company number that sends every event becomes a channel people mute, and a muted channel is worse than none, which is the argument in an alert that rings for everything.

A person should carry the traffic where the answer depends on trust rather than information. A negotiation — rates are agreed between people. A chase: where is the lorry from a company number is a form letter, and from the man who placed the order it is a question with somebody standing behind it. A site instruction, where the supervisor telling a contractor to stop a pour needs to be the supervisor.

A system that handles only the first kind does not remove the second. It pushes it onto personal phones, unrecorded, which is roughly what already happens in most offices, and why WhatsApp is the interface whether anybody designed for it or not.

How we settled it#

Both, with a rule about which.

A person can link their own work number, and their documents and signature requests then leave from it — the vendor sees the colleague they know. Those personal lines are structurally barred from carrying company-wide announcements: a broadcast can never go out over somebody's own number, whatever anybody configures.

For a message to an outside number, we send from the line on which the last conversation with that number travelled. If that line cannot send, it goes from the office number and says nothing about why. A vendor need not be told which colleague was unavailable.

The questions to ask the vendor#

• Where does a reply go? Into a shared inbox with a named owner, onto a screen inside the software, or nowhere. "Nowhere" is a real answer and it is rarely volunteered. Worse is a reply that arrives but is routed as general noise when it was actually a request, which is the failure in filed as chatter.
• Is the conversation kept when the person leaves? For a company number, usually yes. For anything per-person, ask precisely what survives the handset, and ask before the first resignation rather than after.
• Can a person opt out, in both directions? Can a staff member decline to have their personal number used for company traffic. Can a recipient stop receiving messages, and is that honoured permanently and across every kind of message, not only the one they complained about.
• What happens to a personal message that lands in a business thread? Because it will. Somebody's family will message the wrong number, a vendor will send a wedding invitation. Ask whether it is stored, who can read it and whether it can be removed.
• What exactly is stored, and for how long? Text, attachments, numbers, delivery and read status. Read status especially, because it is a fact about a person and it will eventually be produced in an argument about whether somebody saw an instruction.
• What happens when a number changes? Ask how the history follows, and what becomes of messages already queued to the old one.

Consent, and rooms you were not invited into#

Two lines are worth holding whatever the software permits.

Ask before you add anybody. A number that reached your system through a contract, a visitor register or a group somebody was once in is not permission to send them things. Asking costs one message and settles it permanently. The rules here move from time to time, so verify the version in force where you operate — the practice stands on its own regardless.

Read only what was addressed to you. If the software can see a group because a staff member's number is connected to it, it can also see conversations that have nothing to do with the company: a family group, a friend's chat, a discussion among workers. Keep only what a record genuinely requires, and be able to say plainly which is which. A person who suspects the system reads everything on their phone will carry a second phone, and then you have neither the record nor the trust.

The short version#

Broadcasts, statements and system alerts belong to a company identity. Negotiations, chases and site instructions belong to a person the other side knows. Choosing one model for both is the mistake.

Ask where a reply goes, what survives somebody leaving, and what is stored and for how long. Then ask before adding anybody, and read only what was addressed to you.