After Vithai Ratanakorn, Governor of the Bank of Thailand (BOT), came out to disclose information that there are two series of 1,000-baht banknotes — approximately 20–30 years old — with a combined value of around 140 billion baht that have gone missing and are not flowing back into the financial system in the normal way.
One interesting measure that is expected to be able to discipline grey money, corruption funds, and illegal businesses is the cancellation of banknotes, or "Demonetization" — a measure that a government or central bank may adopt by announcing that certain banknotes or certain denominations "cease to be legal tender."
However, a period may be set for the public to exchange the old banknotes for new ones or to deposit them through the banking system.
**Targeting the elimination of off-system money, grey capital, and corruption**
This measure differs from the normal issuance of a new series of banknotes, because Demonetization aims to give existing banknotes currently held by the public an expiry date for their use. If they are not exchanged or deposited within the stipulated conditions, those funds will no longer be able to be used to purchase goods, settle debts, or circulate in the economy.
In policy terms, Demonetization can be used as a tool for dealing with "off-system money" — particularly large amounts of cash hidden outside the banking system — whether it be money from corruption, grey capital from illegal businesses, tax-evaded money, laundered money, or even counterfeit banknotes.
**Squeezing grey and illegal money "out of hiding" before inspection**
The key mechanism is this: once the state announces the cancellation of existing banknotes, those holding large amounts of cash will have few options — either let that money become worthless, or bring it into the banking system to exchange or deposit.
This is precisely the point at which the verification process begins, because bringing a large sum of money into the system will inevitably leave a financial trail, and may lead to checks on identity, the source of the funds, tax obligations, or links to illegal transactions.
As for counterfeit banknotes, the impact is even more straightforward — the moment the old series of banknotes is cancelled, counterfeit notes modelled on that series lose any avenue for recirculation, while attempting to exchange them through a bank also becomes far easier to detect.
Nevertheless, Demonetization does not mean that "all illegal money will disappear entirely," because holders of such money may attempt to disperse it through other individuals, purchase assets, convert it into gold, foreign currencies, or find ways to bring the money into the system through various channels before the measure takes full effect.
**A "powerful medicine" the state must have a plan to manage**
Nonetheless, Demonetization is comparable to a "powerful medicine" that can force enormous amounts of cash back into the state's sight in a short period of time — but at the cost of a high economic price. The government must have robust countermeasures in place without causing liquidity problems for ordinary people's money.
In addition, there must be a sufficiently strong banking system, identity verification system, and transaction monitoring measures; otherwise, illegal money may simply change channels rather than being eliminated.
**India once cancelled large banknotes overnight**
A major example occurred in India on 8 November 2016, when the government of Prime Minister Narendra Modi announced that the existing 500- and 1,000-rupee banknotes would cease to be legal tender. Those two denominations accounted for a very high proportion of the cash circulating in the system at the time.
The Indian government stated its reasons as wanting to deal with black money, tax evasion, counterfeit banknotes, and money linked to illegal activities and the financing of terrorism, while opening the way for the public to deposit or exchange old banknotes through the banking system within a specified period.
**The lesson from India — it's not just about recalling the money, but tracing it back to its owner**
The underlying principle is that those holding money legitimately can deposit it through the bank as normal, while those concealing large amounts of cash they cannot explain the origin of must decide whether to forfeit that sum, or agree to bring it into the system — thereby leaving a trail for the state to investigate.
The India case became an important lesson for the world, reflecting that Demonetization can genuinely be used as a tool to "force cash out into the open." But for it to effectively discipline criminals, grey money, or counterfeit money networks, the state must also prepare to scrutinise "the money that returns to the system — where it came from, and who it belongs to."
