Skip to content

Device testing software for phone refurbishers

Why Passfone

A description costs nothing to write. A measurement can be checked.

Most phones sold today are not new, and almost nothing about their condition can be verified by the person buying one. This is what that costs, and what we do about it.

The market nobody can check

+3.2%

used smartphone shipments, 2025

against +1% for new

IDC, August 2025

$78.6bn

refurbished and used handsets, 2026

$135.4bn forecast by 2033

Persistence Market Research, 2026

71%

held by third-party channels

independents, aggregators, local sellers

Persistence Market Research, 2026

The total is not the interesting part. Who handles the phones is. Most of them never pass through a manufacturer or a large platform — they pass through thousands of small workshops, each with its own idea of what a good phone looks like.

Every phone has a life story, and it gets shorter with each telling

A phone is bought new. It is sold on, and sold on again — often several times as newer models arrive. At each step fewer people know what actually happened to it: how the battery has aged, whether it has been opened, which parts are the ones it left the factory with.

The person at the end of that chain knows nothing at all. They are also the one paying.

What goes wrong, in three layers

1

The words mean nothing

There is no single industry standard for grading. Every seller defines their own grades, so “Grade A” means whatever the person writing it decided it means.

In the wholesale trade it is put more bluntly still: there is no legal difference between “refurbished”, “renewed” and “certified pre-owned” unless a contract says there is.

Two phones described identically can be in entirely different condition, and both descriptions are accurate — because a description was never a measurement.

2

The numbers can be faked

Battery health is the figure most buyers look at, so it is the figure most worth altering. Software exists that rewrites it. So does hardware: a component costing as little as £1.50, connected to the battery, suppresses the warning the operating system would otherwise show, leaving a worn battery reporting as healthy.

Standard quality-control procedures do not find it without opening the phone.

The economics explain the rest: most insurers and trade buyers will only take a handset with at least 85% of its battery capacity left. £1.50 turns a phone they would refuse into one they will buy.

Mobile News, 29 October 2024

3

Sometimes it is simply fraud

Used handsets repackaged and sold as new. Counterfeit parts and accessories fitted during repair.

Consignments of this kind are seized by regulators regularly, in many countries. It is the smallest of the three layers and the only one anybody prosecutes.

Why testing software has not fixed this

Software that tests phones has existed for years, and some of it is good. But all of it produces a report that belongs to the seller — a PDF, a screenshot, a printout.

The seller can edit it. They can crop it. They can show a report from a different handset, or simply not show the one that came out badly.

A report the seller controls is not evidence. It is the seller’s word, in a different format.

What Passfone does instead

We do not issue a report. We keep a record the seller does not control.

Every Device Passport is signed in our cloud and published on our page. The buyer scans the QR code and sees the original, not a copy of it.

Three things you will not find elsewhere

Measurements, not ticks

Not “battery: OK”, but the reading itself. The specimen passport on our home page records Good · 118 cycles, and 37 tests with none skipped.

A number can be argued with. A tick cannot.

The machine does not judge what it cannot measure

Where a sensor is the worse instrument — vibration, flash, cameras — a technician confirms the result, and the passport records that a person did, and which one.

A result with no pass, no fail and no stated reason is not allowed to exist. It would freeze the bench, and it would settle nothing.

The document outlives the seller

Each passport is signed with Ed25519, and the public key is published. Anyone can verify a passport against that key without asking us anything.

That stays true whatever happens to the company that issued it — or to ours.

What a passport is, and what it is not

A Device Passport is the refurbisher’s own record, made permanent. The tests run on their bench, by their technician, and the passport is issued in their company’s name — that name is on the document and inside the signature. It is not an independent inspection, and Passfone does not stand behind the phone.

What we add is that the record cannot be edited afterwards, cannot quietly become a different record, and can be checked by anyone holding the device. A passport for a phone nobody tested would have to be made deliberately, by a named person, in a company that signed its name to it.

That is the whole difference between a description and a record. A description costs nothing and belongs to nobody. A passport costs a test and belongs to whoever put their name on it.

What we are trying to do

Make trust between buyers, private sellers and refurbishment companies something that can be checked rather than asserted.

Most refurbishers are honest. They compete against descriptions that cost nothing to write, and until now they had no way to show the difference. That is what Passfone is for — not to catch the dishonest, who will find other ways, but to give the honest ones something they could not buy before.

A way to prove it.

Verify a device

Sources

Estimates of market size differ between research firms; forecasts for 2033 range from roughly $99bn to roughly $209bn. We quote the more conservative of the figures we can attribute to a named firm and say whose it is.