The -115 dBm line and the evidence file every telecom coverage claim now needs

Australia's biggest mobile operator advertised coverage across 3 million square kilometres for years. A rival pushed the competition regulator to act on it, and the regulator declined. Why it declined is the useful part. The ACCC said it would not pursue Telstra "based on the technical complexity and evidentiary challenges in establishing that these claims were false or misleading." Those difficulties came from the fact that Telstra's claims of geographical coverage "were made at a time when there was no consistent way to assess mobile coverage". That defence has now gone. ACMA's mobile coverage mapmapUsing software to automate repetitive marketing tasks and campaigns, enabling personalisation at scale across channels like email, web, and social.View full definition → standard will see mobile signals below -115 dBm labelled as "no coverage", and the ACCC expects telcos to match their geographical coverage promises to the maps issued under this regime, and when weighing later complaints about deceptive network claims, it will check whether those promises match the published maps.

The same thing is happening in other markets. Regulators and self-regulators now hold shared yardsticks, rivals bring the challenges, and the tolerance for vague claims is shrinking. My argument in this piece is simple: for a telecom operator, the claim is only as good as the evidence file behind it. That file has to exist before the copy is written. It has to match the broadest reading a consumer could reasonably take, it needs an expiry date, and part of it must be shareable with an adversary. Operators that work this way keep their superlatives. Operators that don't usually lose them in a ruling published after the media budget is spent.

How do you substantiate a telecom network claim before launch?

You substantiate it by writing down what a consumer will take the claim to mean, then holding dated evidence that proves that meaning, before any creative is approved. Everything else is process. One rule ties the steps together, and it fits on a whiteboard.

The claim ledger rule: every network claim gets one row with five columns: the exact words, the broadest reasonable reading, the metric and dataset that prove that reading, the date the proof expires, and the version you could hand to a rival. If column two is wider than column three, change column one.

Step 1: write the consumer's reading before the claim

Start the row with what a reasonable customer hears. Ignore what the network team meant. Vodafone UK found out how this works in January 2026. The ASA held that consumers viewing the six ads were likely to interpret "The Nation's Network" as an objective assertion of superiority, for example, that Vodafone was more popular, had more customers, or offered better coverage or reliability than other UK network providers. Vodafone argued the line was a corporate positioningpositioningThe mental space you want your brand to occupy in your target customer's mind relative to alternatives.View full definition → statement or strap line that was not capable of objective substantiation. That argument failed because nearby copy changed the reading: references to "99% UK population coverage" and "London's Best Network" reinforced comparative readings of the tagline.

Verizon hit the same problem with a word. Its "America's largest network" disclosure relied on postpaid connections, but T-Mobile argued that in the telecom industry, "largest network" typically refers to geographic coverage or population reachreachThe number of unique people exposed to your message in a given period. Unlike impressions, reach counts each person once, no matter how often they see it.View full definition →, not subscriber numbers. NAD found the phrase "largest network" to be ambiguous, potentially conveying different messages to consumers. In telecom, "largest", "best", "fastest" and "most reliable" each point to a different engineering metric. Write down every one a viewer could reasonably pick.

Step 2: match the metric to the words, then match the breadth

Once you have the reading, find the dataset that proves it. Breadth is where most operators fail. When T-Mobile defended "Best Unlimited Network" with Ookla and Opensignal speed data, NAD concluded that even if it accepted the evidence as reliable, the evidence didn't match the breadth of the "Best Unlimited Network" claim. Speed evidence supports a speed claim. It doesn't support a claim about the whole network.

Third-party awards make this harder because they disagree with each other. Ookla, which sells network testing data and has owned RootMetrics since 2021, reported that in 2H 2025 T-Mobile posted the fastest national median download speed at 374.5 Mbps and led 5G availability at 95.2%, while RootMetrics gave Verizon seven U.S. RootScore Awards in 2H 2025, including the Overall RootScore Award. Both operators can make a claim from the same report. Neither can claim more than its own category.

Fixed broadband in the UK has a stricter rule. ASA guidance says numerical speed claims in broadband ads should be based on the download speed available to at least 50% of customers at peak time and described in ads as "average". Your evidence file therefore needs median peak-time data from your own customer base. A lab figure or a network design figure won't do. The positive case is T-Mobile Fiber against Charter this autumn: NAD also upheld the claim that T-Fiber does not slow during peak hours, because the claim was narrow and the evidence covered exactly that.

Step 3: reconcile your marketing map with the regulator's map

Many operators run three coverage maps: the one engineers model, the one filed with the regulator and the one marketing publishes. Treat any gap between them as risk. In the US, the FCC will now automatically remove a provider's coverage from the National Broadband Map when an audit or verification finds the data inaccurate, rather than requiring providers to file corrected data within 30 days. A coverage claim that leans on areas your BDC filing no longer shows is a claim you have contradicted yourself.

Worked example, Telstra (public figures, my arithmetic). Telstra's touted 3 million square kilometres used a broader -122 dBm benchmark, which captures weaker, less consistent coverage. Without an external antenna, coverage is around 1.9 million square kilometres, according to analysis of figures the telco has provided to the ACCC. That leaves 1.1 million square kilometres, about 37% of the headline, depending on equipment most customers don't own. Now look at the comparison. Optus claims 1.1 million square kilometres of coverage, while Vodafone owner TPG reports around 1 million. Against Optus, the advantage falls from roughly 2.7 times to roughly 1.7 times. It is still a lead and still worth advertising, but a 2.7x claim can't be supported on a handset-only basis. A ledger row would have shown this before any rival did. Telstra's own defence, a 60,000km nationwide drive program, showing usable service even at weaker signal levels, is exactly the kind of evidence that belongs in the file, labelled with the threshold it supports.

Step 4: split the file into a disclosable tier and a confidential tier

In December 2025, NAD said it would refer T-Mobile to the FTC and state attorneys general after the carrier declined to take part in an inquiry where at issue was T-Mobile's claim of superior 5G capacity of its network compared to its competitors. The claim was that T-Mobile's 5G service offers 40% more 5G capacity than competitors. T-Mobile said it believed the claim was true but had serious confidentiality concerns with any information that would have to be shared in an NAD proceeding initiated by AT&T. Whatever the merits, an operator that can't show its proof without exposing spectrum and site data to a rival has an evidence file that doesn't work in practice.

Build two tiers from the start. Tier one holds methodology, test dates, sample sizes and aggregated results, and it can go to a rival's lawyers. Tier two holds site-level engineering data, shared only under protective terms. Each ledger row should point to both.

Step 5: make the verification route live at the first impressionimpressionThe total number of times an ad or piece of content is displayed, regardless of clicks. Each display counts as one impression, even to the same person.View full definition →

UK comparative claims need a verification route, and the ASA checks whether it works. In its July 2026 ruling on EE's "fastest growing broadband provider" poster, the ASA noted that the documents were not on the site at the point of the first use of the advert, and that the page required significant scrolling and this was not a "clear route to verify the claims in the ad". Publish the verification page before the first impression serves, and put the claim's basis at the top of it.

Step 6: give every row an expiry trigger

Speed awards cover set periods, BDC filings are biannual, and network loading shifts as rivals refarm spectrum. Each ledger row needs a hard expiry date, plus triggers that force a re-check: a new award cycle, a new regulatory filing, or a competitor's network launch in a claimed metro. Thesubstantiation discipline for network claims goes stale in a quarter if nobody owns the calendar.

Where telecom evidence files break under challenge

The common failures repeat across markets:

• Treating a tagline as exempt. Vodafone relied on an April 2025 ruling that cleared one heritage execution. The January 2026 ruling went the other way because the creative had changed. Each execution needs its own row.
• Commissioning research that asks the wrong question. In the earlier Vodafone case the ASA said "the questions did not specifically ask about comparability". If you plan to use consumer research to defend a reading, the questionnaire has to test that exact reading.
• Applying area data to individual households. The One Broadband sent "your current connection 30Mbps" mailers, and the ASA upheld the complaint relating to the London Circular as these were sent to households which had access to full fibre broadband. Personalised network claims need household-level evidence.
• Leaving out the charges that come with coverage. Starlink's £0 kit ad was banned because it did not include the price of the 12-month residential service plan, which applied to all consumers. A capacity-based demand surcharge is a network fact and belongs in the ledger.
• Using the referee's rulings as ammunition. After AT&T's Luke Wilson spot, NAD demanded that the carrier remove both the commercial and press release. Companies aren't supposed to use NAD releases in promotional material.
• Forgetting wholesale partners. In Australia, Optus, Telstra and TPG must also provide their partner companies with maps for use by their customers. MVNOs repeat your claims, so the ledger needs to cover their copy too. Put that check into yourpre-launch sign-off.

What to do on monday

• List every live speed, coverage, reliability and capacity claim across TV, out-of-home, retail point of sale, app store listings and MVNO partner sites.
• For each claim, write the broadest reasonable reading in one sentence and give it to someone outside marketing to challenge.
• Compare your published coverage map against your latest regulatory filing (BDC in the US, the ACMA standard map in Australia) and flag every area where the marketing map shows more.
• Check that every UK broadband speed figure is a peak-time median from your own customers and is labelled "average".
• Open every verification URL on a phone and time how long it takes to reach the claim's basis.
• Ask engineering and legal to separate one current claim's evidence into a tier you could share with a rival and a tier you couldn't.
• Put an expiry date on every claim tied to an award, and give one named person the job of re-checking it.

The ACCC dropped the Telstra matter because no shared yardstick existed. In Australia, the US and the UK one now does, and your competitors can measure your claims with it. Run your own claims against it first and narrow the copy wherever the evidence falls short.

FAQ:

Q: What speed figure can a UK broadband provider legally advertise?

A: UK broadband ads can quote a numerical speed only if it is based on the download speed available to at least 50% of customers at peak time, and the ad must call it "average". The ASA has applied this rule since 2018, replacing the older "up to" standard. That means operators need median peak-time data from their own customer base.

Q: Can a telecom operator use an Ookla or RootMetrics award in advertising?

A: Yes, a telecom operator can cite an Ookla or RootMetrics award, but only for the category and period the award covers. NAD rejected T-Mobile's "Best Unlimited Network" claim because speed and latency data didn't match how broad the claim was. In 2H 2025, T-Mobile led median download speed while Verizon won the Overall RootScore, so each carrier could claim only its own category.

Q: What happens if a carrier refuses to take part in an NAD challenge?

A: A carrier that declines an NAD challenge gets referred to the FTC and state attorneys general, and NAD may also alert the platforms running the ads. That happened to T-Mobile in December 2025 over its claim of 40% more 5G capacity. T-Mobile cited confidentiality concerns about sharing evidence with AT&T, which is why evidence files need a tier that can be disclosed.

Q: How does Australia's mobile coverage map standard affect advertising claims?

A: Australia's ACMA coverage map standard labels signals below -115 dBm as "no coverage", and the ACCC says it will check future coverage claims against the published maps. Telstra's 3 million square kilometre claim used a weaker -122 dBm benchmark. Analysis of its ACCC figures put coverage without an external antenna at around 1.9 million square kilometres.

The full course on this sector:Marketing in Telecom.