How Do You Bill for a WhatsApp Conversation? The Question Cost Law Hasn't Answered

In December 2025, the Senior Courts Costs Office delivered a judgment that should have sent a chill through every law firm in England and Wales that uses WhatsApp with clients.

In MacInnes & Anor v DWF Law LLP [2025] EWHC 3252 (SCCO), Costs Judge Nagalingam debarred DWF; a major firm; from participating in a detailed assessment hearing after it failed to disclose WhatsApp messages that it had charged for on its invoices. The firm's internal policy treated WhatsApp as outside the formal file. The judge disagreed. If you charge for it, he said, it forms part of the file; and if it's part of the file, you must disclose it.

The profession sat up. Legal Futures covered it. LinkedIn lit up. The message was clear: WhatsApp billing is real, and if you're doing it, you'd better be able to produce the messages.

But here's what nobody noticed: the judgment told firms they must disclose WhatsApp messages they've charged for. It didn't; and couldn't; tell them how to charge for those messages in the first place. Because the answer to that question doesn't exist in the rules.

The gap in the rules

Practice Direction 47 of the Civil Procedure Rules, paragraph 5.22, is the foundational text for billing communications in detailed assessment:

"Routine letters out, routine e-mails out and routine telephone calls will in general be allowed on a unit basis of 6 minutes each, the charge being calculated by reference to the appropriate hourly rate."

"The court may, in its discretion, allow an actual time charge for preparation of electronic communications sent by legal representatives, which properly amount to attendances provided that the time taken has been recorded."

So the framework offers two categories for communications:

1. Routine; letters, emails, phone calls; billed at 6-minute units each. One email = one unit. One letter = one unit. One phone call = one unit. Simple.

2. Attendance-level electronic communications; billed at actual time, provided the time has been recorded. This covers substantive emails that amount to real legal work, not just "Dear Sir, please find attached."

Neither category maps to WhatsApp. And the rules were written in a world where WhatsApp didn't exist.

Why the email unit model breaks for WhatsApp

The 6-minute unit model works for emails because emails are discrete. One email in, one email out. Each is a self-contained piece of work. You read it, you respond, you move on. Billing one unit per email is crude but defensible; the unit includes perusing the incoming email and composing the outgoing one.

WhatsApp doesn't work like that. A WhatsApp exchange is a conversation; a series of short messages sent back and forth over minutes or hours. A single "conversation" might involve 20 messages over 15 minutes. If you treated each message as a 6-minute unit (as you would with emails), that's 120 minutes of units for 15 minutes of actual work. That's not just overbilling; it's indefensible on assessment.

But if you treat the entire conversation as a single 6-minute unit, you're significantly underbilling for substantive work. A 45-minute WhatsApp exchange discussing strategy, advising a client on a settlement offer, and reviewing a document they've sent through is worth far more than one unit.

The honest answer is that WhatsApp conversations are closer to phone calls than emails. They're real-time, interactive exchanges. But unlike phone calls; where you typically have a start time and an end time; WhatsApp conversations don't have clear boundaries. Messages arrive throughout the day. The exchange starts, stops, resumes, stops again. When does one "call" end and another begin?

The rules don't say. The Law Society's Practice Advice Service guidance, updated May 2023, discusses routine communications and attendance-level electronic communications but doesn't mention WhatsApp or instant messaging. The SRA's July 2024 thematic review acknowledged that solicitors use WhatsApp with clients but focused on record-keeping and supervision; not billing methodology. The MacInnes judgment addressed disclosure, not billing methodology.

The result is a genuine lacuna: solicitors are using WhatsApp with clients every day, billing for that work, and there is no published guidance; from the SCCO, the Law Society, the SRA, or any costs authority; on how that billing should be structured.

Our proposed framework

At OrdoLux, we've thought about this carefully. We don't claim to have the definitive answer; and we want to be clear that this is a proposed framework, not a statement of what the law requires. But we believe the following approach is the most defensible interpretation of the existing rules, and it's what we've built into our platform.

The principle: time-based billing, not message-based

WhatsApp conversations should be billed by time, not by message. This places them in the second category of PD 47 5.22; "electronic communications sent by legal representatives, which properly amount to attendances"; where "an actual time charge" is allowed "provided that the time taken has been recorded."

A WhatsApp exchange where a fee earner advises a client, reviews a document sent through the chat, and discusses next steps is substantive legal work. It properly amounts to an attendance. The time should be recorded and billed at the hourly rate.

The 6-minute gap rule

The challenge is defining what constitutes a single "attendance" within a WhatsApp conversation. Unlike a phone call, a WhatsApp exchange doesn't have a clear start and end. Our proposed rule:

1. An active conversation is one where messages are being exchanged with no gap of more than 6 minutes between any two consecutive messages. As long as the fee earner and client are messaging back and forth within 6-minute windows, the conversation is "live" and time is accruing.

2. When the conversation goes quiet for more than 6 minutes, the active session ends. All time up to the start of that gap is recorded as one continuous attendance.

3. A new message after a 6+ minute gap starts a new active session. Time begins accruing again from that message.

This gives you discrete, measurable time blocks; each one a defensible "attendance"; with the 6-minute threshold matching the standard unit increment used throughout cost law.

An example

A fee earner and client exchange messages from 14:00 to 14:15 (15 minutes of active conversation). The client then goes quiet. At 14:32, the client messages again, and the conversation resumes until 14:42 (10 minutes).

Under this framework:

• Session 1: 14:00–14:15 = 15 minutes = 2.5 units (rounded to 3)
• Gap: 14:15–14:32 = 17 minutes (>6 minutes) = session ends
• Session 2: 14:32–14:42 = 10 minutes = 1.5 units (rounded to 2)
• Total: 5 units (30 minutes) for 25 minutes of actual conversation time

This is defensible, transparent, and directly tied to the time actually spent. It avoids both the overbilling of per-message units and the underbilling of treating a substantive conversation as a single routine unit.

What about routine WhatsApp messages?

Not every WhatsApp message amounts to an attendance. "Thanks, received" or "I'll call you tomorrow" is a routine communication; the equivalent of a routine email. For these, the 6-minute unit model from PD 47 5.22(1) applies. One routine exchange = one unit, as with a routine email.

The judgment call; and it is a judgment call; is whether the exchange "properly amounts to an attendance." The same test that applies to emails under 5.22(2) applies here. If the substance of the exchange involves legal advice, strategy, document review, or substantive discussion, it's an attendance. If it's an administrative acknowledgement, it's routine.

How OrdoLux handles this

We've built this framework directly into OrdoLux's WhatsApp integration. Here's how it works:

1. Fee earners communicate with clients via WhatsApp through OrdoLux's dedicated WhatsApp numbers. All messages are automatically linked to the relevant matter file.

2. When a fee earner wants to record time for a WhatsApp conversation, they can screenshot the conversation and share it with OrdoLux. OrdoLux reads the conversation; extracting timestamps from the WhatsApp interface; and applies the 6-minute gap rule automatically.

3. OrdoLux calculates the time blocks, applies the units, and creates a time entry on the matter. The entry includes the date, the duration, the number of units, and a reference to the conversation (which is saved to the matter file for disclosure purposes; directly addressing the MacInnes requirement).

4. The conversation is saved to the matter's SharePoint file. If you charge for it, it's on the file. This is what MacInnes demands, and what the SRA's 2024 review recommended.

The entire process; from WhatsApp conversation to recorded, filed, and billable time entry; takes seconds. No manual time recording. No forgetting to save the chat. No risk of a MacInnes-style disclosure failure.

Why this matters now

The MacInnes judgment made one thing clear: courts will treat WhatsApp like any other communication medium for costs purposes. If you bill for it, you disclose it. If you don't disclose it, you face sanctions; up to and including debarment.

But the judgment also exposed a question that the profession has been quietly avoiding: if we're billing for WhatsApp work, what's the right way to do it? The SCCO didn't answer that question. The Law Society hasn't. The SRA hasn't. The rules were written for a world of letters and emails, and WhatsApp doesn't fit.

We've proposed a framework that we believe is the most defensible interpretation of the existing rules; one that maps WhatsApp onto the "attendance" category in PD 47 5.22(2), uses a 6-minute gap rule to define discrete attendances, and ensures both the time and the underlying conversation are recorded. We've built it into OrdoLux because we believe the tools should support the framework, not the other way around.

We may not have the final word on this; that's for the costs judges, the Law Society, and ultimately the Civil Procedure Rules Committee. But in the absence of any published guidance, we think it's better to have a defensible, transparent, and consistent framework than to leave every fee earner to improvise.

A note on scope

This article sets out OrdoLux's proposed approach to WhatsApp time recording. It is not legal advice. The framework described here is our interpretation of how the existing rules in Practice Direction 47 could be applied to instant messaging, and we believe it is defensible. But it has not been tested in detailed assessment, and we are not suggesting that it represents the only correct approach. Firms should consider their own circumstances, their own areas of practice, and their own costs agreements when deciding how to record and bill for WhatsApp communications. If in doubt, seek advice from a costs lawyer or contact the Law Society's Practice Advice Service.

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References: Practice Direction 47 of the Civil Procedure Rules, paragraph 5.22; MacInnes & Anor v DWF Law LLP [2025] EWHC 3252 (SCCO), Costs Judge Nagalingam; Law Society Practice Advice Service Q&A on routine communications (May 2023); SRA thematic review of asylum legal services (July 2024). OrdoLux is an independent case management platform and is not affiliated with the Senior Courts Costs Office, the Law Society, or the Solicitors Regulation Authority.