This is a Firefox translation of a German article, but it shows they’re ramping up cash serial number tracking. This is along the lines of Automatic License Plate Reader cameras, where there is a database of your travels even if you disable the GPS on your smartphone or connected car. The interesting part is cash is thought to be private, but soon you’ll have to use a privacy minded cryptocurrency to have any privacy with financial purchases. But some governments (the EU next year) are already making Monero and Zcash illegal as well as getting them removed from exchanges, so that tells the tale that they don’t want you to have any financial privacy, and really they want you on a centralized service where they can freeze or take your funds if you’re not doing what they want, like eating too much red meat.
https://netzpolitik.org/2025/bargeld-tracking-du-hast-ueberwachungsinstrumente-im-portemonnaie/
Cash is considered an anonymous means of payment. The serial number shows which routes take bills. The infrastructure for cash tracking is being further expanded. They also use German security authorities to investigate.
By Martin Schwarzbeck, Marc Lagies
He is waiting for his use in your wallet. He has been on the road for many years and reports his location whenever he is scanned – which happens quite often. He can make your interests and needs comprehensible, identify personal connections and business relationships.
It is a banknote, a printed strip of cotton fibres with two letters and a ten-digit number chain in the upper right corner on its back – its unique serial number. An exemplary twenties perhaps. He is registered in countless positions in the course of his life. It runs through machines for tickets, parking tickets, snacks, coffee, cigarettes, photos or gambling, and repeatedly equipment that counts, checks and sort money. Machines with modern banknote processing modules can track serial numbers.
Even if a person collects the banknote, it is not protected against automated serial number detection. The revenues of most stores are collected daily by money transport companies. And they hunt the money in their cash centers by means of banknote examination and sorting machines, which can also read out serial numbers.
The comprehensive use of automated serial number detection provides the technical infrastructure for a detailed tracking of the trip of banknotes. And there are increasing efforts to store and merge the data generated. Cash thus becomes a monitoring instrument.
Law enforcement agencies are already using serial number tracking for investigations. The industry wants to optimise cash logistics. And also curious people track cash as recreational employment. “Because it’s fun!” says a website for passionate euro banknote trackers.
There are a lot of payments that some people prefer to process anonymously: spending on health problems or sexual game types, for example, but also donations to political organisations. If the appearance a high official has taken place today comes up in a workplace for sex workers tomorrow, it can make him blackmail. If an uncouthed person with a cracked banknote supports a queer NGO, this can threaten its existence in some places.
Cash is popular – also because of data protection
More than 80 percent of Germans see data protection an argument for cash payments. More than two thirds believe that cash is of great importance to society. According to the latest survey, in 2023, more than half of all payment transactions were processed with cash. The people in Germany bunker 395 billion euros in cash.
Data protectionists warn against a new form of mass surveillance and the immense interference of fundamental rights that potentially means cash tracking. The Bundesbank points out that privacy is an important advantage of cash for many people. People in Germany have the right to informational self-determination. The German Central Bank itself is pursuing the path of certain banknotes on certain occasions. “It can be assumed that reading serial numbers will be established permanently and irreversibly,” she writes in an internal document from 2021, which netzpolitik.org has published via information request.
Anyone who plunges into the world of cash tracking perceives money differently. The shams then tell stories. In this article, we explore how cash industry, law enforcement agencies and central banks are working on cash following worldwide. We look at how German police and prosecutors use cash tracking. And we get to know a rather unknown start-up that collects serial numbers at a central node of the cash circuit and sells insights into the database to investigating authorities.
“A promising technology”
The technology needed to track the path of a banknote already exists and is used in numerous countries. The lobby association of central banks and companies in the cash industry, the International Association of Currency Affairs (IACA), considers cash tracking, named “Cycle-Cash Visibility and Collaboration”, to be a promising technology. It is intended to make cash more efficiently manageable.
The award for particularly advanced cash tracking solutions presented by IACA at the end of May shows where the industry sees the future. The Japanese company Glory Ltd obtained it with a number of projects in Europe where banks and money transport companies are recording serial numbers and automatically searching for numbers involved in criminal acts.
The company also developed Kibango, a software for analysis and management of serial numbers. This can be used to import serial number search lists. According to the company, any banknote that would be withdrawn from an ATM could be tracked. Such software triggers an alarm once it is scanned an alarm if our example twenties is listed on a search list.
These states are already tracking cash very accurately
In China, ATMs have to assign the serial number to an account to each banknote they pay. Thus, with every appearance, it is clear who circulated it. Some devices even collect biometric data of the forwarding person.
In South Africa, the central bank is conducting real-time tracking of cash movements, says Pearl Kgalegi, head of the local currency management, at an IACA meeting. Information from ATMs is collected in a central database and shared with security authorities. Since this has happened, there have been more arrests, for example after ATM blasts.
The Canadian Central Bank maintains a database of data on all Canadian banknotes in circulation to collect signs of wear. The Bank of Israel also has a banknote database.
In the US, an association of 10,800 U.S. law enforcement agencies, called Regional Information Sharing Systems (RISS), operates a network of money counts and a database where the captured banknotes are stored with photos and serial numbers. Investigators from participating authorities can search this database. According to an RISS brochure, a drug wholesaler was captured in Hawaii after money had been tracked that had been confiscated, registered and handed over to a customer.
German security authorities are also currently using registered banknotes as an investigation tool. And there are efforts to take their cash tracking to a whole new level.
These crimes persecute the German police with cash tracking
The German police have been using serial numbers of banknotes to track cash streams since the 1970s at the latest. This may look like this, for example: a person is kidnapped, the kidnappers make a ransom demand. However, before the money is handed over in the suitcase, police officers capture the serial numbers of the notes to be handed over in a police database. In this database, they also note serial numbers of banknotes that were captured at ATM riots or attacks on money transporters. If, for example, large quantities of cash are noticed at a border crossing or when searching for a house, the police or customs will check whether there are sought-after notes. Depending on where the money reappears, they can draw conclusions about the perpetrators, depending on where the money reappears.
The serial numbers are also linked to people in the police database. “In the police information network, it is possible to link various information categories, including personal data,” writes the Bremen police. Parallel to the storage in the national database, it is also possible to store the Schengen Information System, in which banknote series numbers can also be sought in Europe.
This means that police notes circulate there. And it may be that you have one of them in your wallet.
Investigators don’t like to talk about this tool. BKA and state police refer to investigationalstaktic reasons, from which they should not provide any information. At the end of May, the Hamburg police even refused a corresponding parliamentary question by Left deputy Deniz Celik. But from the few that the police authorities then answered can be seen that and how banknote series numbers are used for investigation.
The Thuringia police write: “When prosecuting money laundering, knowledge of serial numbers can help to track illegal cash flows and identify the persons or organisations involved.” As an example of the police, the Bavarian police mentions terrorist financing, where cash tracking could enlighten “cash flows or their origin”. The police of other federal states confirm that serial numbers of banknotes are recorded and searched for investigations in various crime areas.
So far, the authorities have to hope that the banknotes wanted will eventually appear at a police or customs control. The opportunity is relatively small. This is probably why investigators regularly ask the Bundesbank whether he has encountered a certain banknote. This is the result of an internal study from 2020, which netzpolitik.org has made public per freedom of information request. At that time, the Bundesbank tested whether it could process comprehensive serial numbers, also in order to meet investigators. She ultimately decided against it. But the investigators can now search for the notes in another database. They may even be connected to a kind of real-time recording of the German cash cycle.
“We listen to cash”
Gerrit Stehle, Managing Director of Elephant & Castle IP GmbH, wants to take the official cash tracking in Germany to a new level. Steal offers a constant, automated mass comparison with circulating banknote series numbers. An interface in the engine room of the cash infrastructure.
His company receives banknote series numbers with the location and time of recording of one of the money transport companies operating in Germany. The money transporters are central points in the cash cycle – most of the notes regularly come by here. Gerrit Stehle researches for security authorities as reviewers in this database. The serial numbers of the notes, the stories of which he traces for authorities, also stores in his system. His company is already working with several German prosecutors and also with security agencies from other countries, he says.
“Our technology makes it possible to track the history of banknotes at the touch of a button,” says Stehle. It could be found out, for example, which notes were in circulation and how often, who have disappeared or who have left the country. “We use data analytics to develop a deep understanding of cash movements and identify cash flows that have potentially suspicious patterns. We listen to the cash, so to speak,” he says. He has been working on the project for seven years, and 15 people are now involved in it.
The Cybercrime Public Prosecutor’s Office of North Rhine-Westphalia (ZAC NRW) has tested the system and presented it in an online training course specialist by public prosecutors from the areas of organized crime, fraud and corruption. The ZAC NRW also lends a money counting machine that reads serial numbers and offers help with data collection. ZAC-NRW head Markus Hartmann says the database is an “instrument used in a manageable number of cases”.
Standing and its partner company rely on a specific monetary countener from the manufacturer Glory Ltd from Japan when it comes to serial number detection, which is the most reliable. Stehle shares the information obtained in the form of expert reports with investigating authorities. They could then compare the data with the statements of the accused and reveal inconsistencies or confirmed omissions. “An example from practice: in one case, a person claimed the money fresh from the bank, but through our analysis we were able to prove that the cash was already much older,” says Stehle.
Authorities should get direct interface
Standing else would like to connect other checkpoints to its cash monitoring network. “Money counting devices are already widely used, for example in the back office of supermarkets, which offers considerable potential. If banknote serial numbers were systematically recorded, assaults on the older sections of the population, money transporters, bank ATMs or retail stores could significantly lose their worth appeal.”
Standings alone sees the danger. The possibility of carrying out anonymous transactions “represents a fundamental pillar of freedom,” he says. But he also sees the downside: cash can be abused to support illegal activities.
The standing goal is to make its system directly accessible to investigators via software licenses subject to pay. Without a detour via the expert. “They could then be connected to the system 24/7 via a user-friendly interface and carry out the corresponding evaluations independently,” says Stehle.
The value transport company from which the data originates does not receive any money. “The company has the advantage that costs can fall because there are fewer attacks and that it can offer retailers and banks the use of this new technology,” says Stehle. He does not want to reveal which of the companies cooperates with him.
The data collected would be with copies in several locations, in a cloud developed in cooperation with Google and Deutsche Telekom, says Stehle. There they are also protected from unauthorised access by US security authorities.
How sensitive are the data?
Steal rights do not see any problems under data protection law. “This is factual data that is not subject to data protection. We do not collect any personal data of the citizens,” he says. The GDPR only protects personal data – i.e. those relating to a directly or indirectly identifiable person. A lot of other data do not fall below, for example weather recordings. But do data about cash flows really have as little to do with individuals as the wind strength?
Luke Hoß, member of the Left’s member of the Bundestag, sees a threat to privacy in cash tracking: “Comprehensive tracking of cash series numbers would provide profound insights into people’s private lives. Not only the way to the baker, but also the trip to a clinic for abortion would be understandable.” The right to privacy must not be further restricted by reference to security. “When authoritarian parties such as the AfD came to power, there is a risk that the processes covered in this party will lead to persecution, even if they are legal according to current legal situation,” he says.
Although Gerrit Stehle speaks of “state data”, he nevertheless shows understanding that the data is not entirely harmless. “They have some potency, such information should not be in private hands,” he says. Therefore, he offers his services only to state agencies. In some cases, there are already interfaces between police case processing tools and its system. “Their tools upload our data to their tools,” he says.
An international patent, which he registered in 2018, shows the future that Stehle can imagine. He calls it the “Nucleus of the Project”. In it, Steal describes an ATM that accepts cash and uses the serial numbers on the notes to recognise whether this money was reported stolen or handed over as part of a ransom breakage. In the case of appropriate findings, he should be able to automatically notify the police or security services. And at petrol stations, according to Stehle’s patent specification, deposit machines could automatically initiate the storage of the appropriate video images when the money is sought.
Customs union chief demands comprehensive cash tracking
Frank Buckenhofer, chairman of the police union in customs, is a committed advocate of the technology for cash tracking. “Banks and monetary courier services include the numbers of the banknotes and their temporal allocation. It would be helpful if this data were brought together and made available to the police and customs authorities,” he says. The data would create a relatively dense network of important information about the path and origin of cash. “And because the mere numbers are not personal data, data protection does not play a role,” he says. The data protection officer of Schleswig-Holstein sees this differently – more on this.
If large quantities of cash were found by police and customs authorities, if Buckenhofer’s hope were to be discovered with the help of registered serial numbers, objections could be determined in the statements. “If, for example, someone at the border is picked up with a million euros in cash or more, which occurs again and again, he can tell the officials every story. For example, that it is ‘saves from the grandma,” says Buckenhofer. But if bills were identified with a money counting machine, which were still in many different ATMs, at petrol stations or supermarkets in the last 48 hours, then the money treatier will break together. “So we urgently need this data, otherwise people can fully satisfy the hucke.”
The technology can also be used to track down former ransom and money from cracked ATMs. For example, the search for suspects can be intensified in regions where banknotes are sought. “The systematic recording of banknotes in a database enables a whole range of uses for the criminal work of customs and police,” says Buckenhofer. He would like to have laws on cash tracking and a private serial number database that customs and police, tax, financial and money laundering authorities can access online.
Data protection officer in custody
Marit Hansen, State Commissioner for Data Protection Schleswig-Holstein, takes a critical view of comprehensive cash tracking. She says: “When serial numbers are stored with the time and location of the collection and this data is collected more and more granularly, you lose the anonymity of cash.” Even if the registration pursues legitimate interests, it could be problematic. “In the overall view, the risk arises that the individual data will be related to people. At a certain threshold, for example, location data from persons could be derived. It would also be possible to see who is interested in what,” she says.
Comprehensive cash tracking would not only create risks for individuals, but also for business secrets and possibly even for internal security, says Hansen. For example, it could be used to obtain usable information about security-relevant persons.
Hansen compares the serial numbers with the printer IDs, so-called Yellow Dots, which are included in color printouts. “These are also just technical data, and yet they can be used, for example, to identify whistleblowers.”
Hansen considers it important that people have a truly anonymous payment option. Because personal or even intimate details could be seen from the payment lanes: more or less healthy eating, addictions, love affairs. “This is information that others do not concern anything. Here people have a legitimate interest in not leaving any traces,” she says.
In another part of this research, we follow the life of a banknote from printing to shredding and seeing where serial numbers are already recorded everywhere. The round trip in the cash cycle shows how the threatening networking of data points would deanonymise cash.