Digital euro holding limit: the cap on what one wallet could hold

A holding limit is a hard ceiling on the balance in a digital euro wallet. A payment that would push the balance above the ceiling is refused or routed on, and no interest is paid on the balance in any case.

The reason is the deposit base of commercial banks. Euro-area banks fund loans largely with customer deposits. A digital euro with no cap would let a household move its current account to a claim on the ECB in an afternoon, and in a stressed week it would let a whole country do it. The cap limits the size of that move in advance. The ECB's own quantitative analysis of the holding limit models the trade-off between a cap high enough for everyday payments and one low enough to leave bank funding in place.

Figures between 500 and 3,000 euros have been discussed in public. The Bruegel analysis of digital euro holding limits works through what each band would mean for payment behavior and for bank funding, and OMFIF asks whose interest the limit serves, since a cap that protects banks also makes the instrument less useful.

The number itself would not sit in the regulation. The ECB would set and publish it, with a duty to report before issuance and to review the figure at regular intervals once the digital euro circulates. Businesses are treated differently from private holders: under the Council's position a merchant could accept digital euros and would have to pass them on, with a holding limit of zero.

The euro area is not alone in capping a retail central bank currency, and the proposed bands differ widely. The Bank of England has discussed 10,000 to 20,000 pounds for a digital pound, with the option of changing the figure after launch. The Bank of Canada has worked with a figure around 25,000 Canadian dollars. The People's Bank of China varies the cap on the digital renminbi by how much identification a wallet carries, so a low-verification wallet holds less.

Against those numbers the euro-area discussion is strict. The Bruegel analysis also notes an academic recommendation of 1,500 to 2,000 euros on financial stability grounds, and points out that average cash held in a wallet in the euro area ranges from about 46 euros in the Netherlands to about 121 euros in Austria, far below every cap under discussion.

The waterfall is what makes a low cap workable at the till. A payment arrives that would take the wallet over the limit, and the excess is transferred straight to the linked commercial bank account. The reverse waterfall runs the other way: a payment larger than the wallet balance pulls the missing amount from the bank account in the same instant, so the payer never has to top up by hand.

Both legs have to clear in the time a card payment takes. That is the engineering problem for a distributing bank. The wallet, the current account and the scheme have to agree on one balance under a few hundred milliseconds, and the account leg has to work when the customer's own bank is in a maintenance window.

German banking associations have argued against the project in its current form, and the deposit question is their main argument. A savings bank or a cooperative bank funds its regional lending book with local current accounts. Every euro that moves into a central bank wallet has to be replaced with wholesale funding at a market price, which changes the margin on a mortgage.

Finance Loop covers the position of the German sector in the digital euro in Germany. The counter-argument from the ECB side is that the cap plus the waterfall caps the outflow by design, and that a bank keeps the customer relationship because the wallet sits next to the account it distributes.

The waterfall creates a contradiction the ECB has not resolved. If a wallet tops itself up from the bank account whenever a payment needs it, a user has no reason to keep any balance in digital euros at all. The holding limit then caps something nobody holds, while the ECB argues at the same time that the digital euro should give a digitalizing economy an anchor in central bank money. Bruegel states the tension plainly: the waterfall removes the incentive to hold digital euros.

The figures the ECB itself publishes also sit well inside its own safety margins. OMFIF reports an estimated effect of 8 to 18 basis points on bank net interest margins under normal conditions, and 9 of roughly 2,000 banks at risk of breaching liquidity buffers in an extreme bank-run scenario, with real concerns appearing only above a cap around 5,000 euros. The paper's question follows from that: whether the limit protects stability or bank margins.

Yes, and it has done it before at a far larger scale. When a deposit moves into a digital euro, the funds land at the central bank, which can lend them back to the bank that lost them. The third series of targeted longer-term refinancing operations reached a peak outstanding balance of about 2.2 trillion euros at rates as low as minus 1 percent, which shows both the instrument and the willingness to use it.

If the central bank recycles displaced funding on comparable terms, a bank's lending capacity is largely unchanged, and the deposit-flight argument loses much of its force. What a bank does lose is the cheap, sticky funding of a current account, and that is the 0.2 percent of GDP in margin that OMFIF attributes to deposit market power.

An offline digital euro would work without a network connection, with the balance held on the device and transferred device to device. That design has no central ledger entry at the moment of payment, so it needs its own cap, set lower than the online one.

The offline balance is also where the privacy argument sits. A payment that never reaches a server leaves no transaction record with the intermediary, which is as close to cash as the project gets. The ECB progress report on the digital euro puts the offline capability in the first release, not in a later one.

A distributing bank would need a real-time link between the digital euro wallet and the payment account, plus the logic that decides which leg fires. In practice that means an always-on account service, a balance check inside the authorization path, and a reconciliation process that can explain every waterfall transfer to a customer who asks why money moved.

The digital euro rulebook is where those duties are written down for every distributor. Teams that already run instant payments have part of the plumbing, since SEPA instant credit transfers forced the same always-on posture on the account side.

Under the Council's position a merchant or company would not hold digital euros at all. A business could accept a digital euro payment, and the amount would be swept to its commercial bank account, giving it a holding limit of zero. The cap under discussion applies to private individuals.

The payment goes through and the excess leaves the wallet in the same moment. A transfer that would take the recipient above the cap is passed on to the linked bank account by the waterfall, so the sender sees a normal payment and the recipient sees the money arrive in two places.