Interbank Deposits: How They Work and Why Businesses Care

Interbank Deposits: this guide explains the core mechanics, illustrates the decisions with examples and identifies the records to check.

A company waiting for a customer payment and a bank managing its settlement obligations both face a timing problem. Their incoming and outgoing cash does not always arrive together. Banks can bridge such gaps by borrowing from other institutions, including through deposits. Understanding that mechanism helps a finance team ask better questions without confusing wholesale bank funding with its own operating account.

What happens in an interbank deposit?

An interbank deposit transfers funds from one bank to another under agreed repayment terms. It creates an asset for the depositing bank and a liability for the receiving bank.

The depositing bank has a claim on the receiving bank. For the receiving bank, the deposit is a funding liability. The parties agree the currency, amount, maturity, interest basis and settlement instructions. A placement may be overnight or for a longer term. In the ordinary unsecured arrangement, repayment depends on the receiving bank’s ability to meet its obligations.

Terminology matters when comparing statistics. The BIS uses a broad deposit-funding category in its international banking analysis that includes customer deposits, interbank funding and repos. That does not mean these instruments have identical legal terms or risks. See the BIS analysis of international banks’ deposit funding.

Consider a simplified banking day. Bank A receives more incoming transfers than it needs for settlement, while Bank B has more outgoing payments than incoming receipts. A placement can move available funds between them. This is a balance-sheet transaction, not a donation of spare money: Bank A expects repayment and evaluates Bank B as a counterparty. The fact that the receiving institution is regulated does not remove that evaluation.

The entrepreneur’s account remains a separate contract. If a company holds a deposit at Bank A, it does not automatically become a direct lender to Bank B when Bank A makes a placement. Nevertheless, the company has an interest in Bank A’s overall resilience. This distinction helps explain why understanding a bank’s funding model is useful without implying that customers control its daily treasury decisions.

How is interest on an interbank deposit calculated?

Interest depends on principal, annual rate, the number of days and the contractual day-count convention. Two confirmations with the same headline rate can produce different cash amounts.

Illustrative calculation, not a market quote: Bank A places $10 million with Bank B for one day at an annual simple rate of 4.50%, using an actual/360 convention. Interest is $10,000,000 × 0.045 × 1/360 = $1,250. The agreed repayment is $10,001,250, assuming performance under the contract.

Changing the convention changes the number: on actual/365, the same one-day calculation produces approximately $1,232.88. A finance team reconciling a confirmation must therefore check the day-count basis, not just the headline rate. Holidays, value dates and maturity dates also belong in that reconciliation.

Extend the same example to a seven-day placement. With all other assumptions unchanged, interest is $10 million multiplied by 4.50%, multiplied by seven, divided by 360: $8,750. That is seven days of simple interest, not an annual return earned in one week. A quoted annual percentage must always be converted to the actual period before comparing cash receipts.

A practical confirmation check has two independent stages. First, match commercial terms to the approved deal. Second, match settlement instructions to previously verified bank details. Correct arithmetic cannot detect a substituted beneficiary account. Keep the agreed rate and calendar assumptions with the calculation so a reviewer can reproduce the amount without asking the original dealer to explain it.

How do interbank deposits differ from other funding?

The distinction is the counterparty and the contract: a corporate deposit comes from a business, an interbank deposit from a bank, and a repo involves securities and a repurchase agreement.

The following comparison separates the key questions to review.

Nor is every transaction in a benchmark funding market strictly bank-to-bank. The New York Fed explains that the US federal funds market includes unsecured dollar borrowing by depository institutions from other depository institutions and certain other entities. Its Overnight Bank Funding Rate methodology distinguishes the markets feeding that measure. A benchmark observation is not a rate promised to a corporate borrower.

Collateral changes the structure of a transaction, but it does not make all other controls unnecessary. A finance reader comparing unsecured funding and repos should ask which assets support the exposure, how those assets are valued, and what happens if repayment or delivery fails. Avoid treating the word secured as a complete credit assessment.

Likewise, a central-bank reference rate, an overnight wholesale benchmark and a customer’s borrowing rate answer different questions. A customer facility may reprice monthly or quarterly, contain a contractual floor, or include a separate margin. Reading the pricing clause is more informative than assuming every movement in an overnight chart passes through immediately and in full.

What risks do interbank deposits create?

The principal risks are nonpayment, unavailable replacement funding, concentration and settlement failure. Short maturity reduces the time exposed but does not make repayment certain.

Credit risk: the receiving institution may not repay. Rollover risk: funding that matures tomorrow may be unavailable tomorrow. Concentration risk: several apparent funding sources may depend on the same group or market. Currency mismatches and operational settlement failures introduce further vulnerabilities.

The Basel Committee’s liquidity-risk guidance emphasizes liquidity buffers, stress scenarios and the possibility that secured and unsecured funding sources deteriorate. For a business, the useful implication is to plan for access to cash under stress, rather than assume that a profitable bank or company can always obtain short-term funding.

Liquidity and solvency are related but different. A borrower can own valuable assets and still lack cash when an obligation falls due. Conversely, temporary access to funding does not establish that the value of its assets exceeds its liabilities. For a business reader, the useful lesson is to examine both the ability to meet near-term payments and the resources supporting longer-term obligations.

Stress also connects risks that appear separate in a spreadsheet. Two banking relationships can depend on the same group, currency market or payment infrastructure. Mapping those dependencies does not predict a failure. It identifies situations in which the company’s assumed backup might become unavailable at the same time as its main provider.

How should a business manage its banking exposure?

Start with legal entities, access to operating cash and a tested payment-continuity plan. A business does not need to trade in wholesale funding markets to manage the effects on its own accounts.

The following comparison separates the key questions to review.

• Map cash balances and credit facilities to the actual legal banking entities.
• Separate immediately available operating cash from term placements.
• Check deposit-protection eligibility under the applicable local scheme; do not assume wholesale exposures receive retail protection.
• Test whether payroll and supplier payments can continue if one bank becomes temporarily inaccessible.
• Review borrowing documents for availability conditions, maturity dates and concentration limits.

For the payment mechanics behind these relationships, see how clearing and settlement work.

Assign an owner to each action. Treasury can maintain balances and maturities; accounts payable can test alternative supplier-payment instructions; an authorized executive can approve emergency transfers. Without named responsibility, a contingency plan often remains a list of intentions. Include the approval route and the location of current contact details.

Use the Kurums Finance hub to connect banking exposure with working-capital decisions. The 13-week cash-flow forecasting guide provides a companion framework for identifying when cash must actually be available. A balance that earns interest but cannot be accessed before payroll is due serves a different purpose from operating cash.

How can a company test whether its cash is really accessible?

Model a temporary loss of access to the main bank, then identify which payments can still be made on time. The exercise should test permissions, available balances and payment routes, not simply the existence of a second account.

Consider a hypothetical company with $600,000 of cash, all at Bank A, and $180,000 of payroll and supplier payments due during the next five business days. It also has an unused account at Bank B. The second account does not provide practical resilience if it has no funds, its signatory has left the company, or payment beneficiaries have not been approved. Counting banking logos would miss these weaknesses.

The team can run a desktop exercise using a small set of real payment dates, without making unnecessary transfers. Record the amount already accessible elsewhere, the time required to obtain additional cash, the people who can authorize it and any limits that apply. Flag payments that cannot be delayed. Then decide which operational changes are proportionate to the business, rather than automatically moving every balance.

For cross-border companies, add currency and local holidays to the exercise. Cash available in one currency may require conversion before it can meet another entity’s obligation. An apparent surplus at group level can coexist with a shortfall in the specific account that must make the payment. The purpose is to expose that mismatch while there is still time to act.

Does deposit protection remove the need to assess a bank?

No. Deposit protection has eligibility rules and limits, while payment continuity also depends on timely access. A company should assess the relevant scheme and its operational exposure as separate questions.

For a US example, the FDIC’s deposit-insurance guide explains coverage by depositor, insured bank and ownership category. Business structure matters: a sole proprietorship is treated differently from a qualifying separate corporation. Opening several accounts at the same institution does not, by itself, create unlimited protection. Apply the current rules to the actual account ownership rather than a trading name on a statement.

This is not a worldwide rule or a determination of any particular company’s coverage. A business operating in another jurisdiction should use the local protection scheme’s official guidance. It should also identify the legal bank holding the deposit. A technology platform, brand name or payment interface may not be the same entity as the deposit-taking institution.

Keep evidence of the assessment with the bank register: account holder, institution, product type, applicable scheme, date checked and unresolved questions. A documented gap gives management something concrete to resolve. An unsupported statement that all money is insured can conceal both an eligibility problem and a continuity problem.

What should appear in a monthly treasury review?

A useful review combines bank exposure, cash timing and actions requiring approval. It should show changes since the previous review and the decisions those changes require.

Begin with average and peak balances by legal banking entity. Month-end totals alone can hide a large concentration immediately after customer collections or before a supplier run. Add term-deposit maturities, committed payments and facility availability. Distinguish money the business owns from funds it holds for someone else, and unrestricted balances from amounts subject to restrictions.

Next, identify exceptions: expired counterparty reviews, inaccessible backup accounts, unexplained confirmation differences or forecasts that rely on an unapproved borrowing extension. Give each exception an owner and a resolution date. The report should make uncertainty visible without presenting every exception as a crisis.

Finally, connect the report to decision rights. The Corporate Governance hub covers the broader setting for oversight and accountability. Management needs to know who may change a deposit limit, accept a temporary concentration or activate a contingency arrangement. Interbank markets explain part of the financial environment; disciplined decisions determine how the company responds to it.

Frequently Asked Questions