Reserves and Customer Deposits

Why Reserves and Deposits Are Easy to Confuse

A bank may hold cash in its own vault and maintain an account at the central bank. Those resources can support payments and settlement, but they are not the same thing as the balances customers see in their deposit accounts. The distinction is important: reserves are assets of the bank, while customer deposits are liabilities of the bank.

The confusion often comes from describing reserves informally as money “held against deposits.” That wording can make reserves sound like deposits themselves. They are not. A reserve is a resource the bank owns or a claim the bank holds on the central bank. A deposit is a claim a customer holds on the bank. The two can be related in a bank’s operations, but they belong to different sides of the bank’s balance sheet.

Definition: Bank reserves are the bank’s vault cash and its balances held at the central bank, as specified for the context being discussed. Both are assets of the commercial bank. A customer deposit is an amount the bank owes to a customer under the terms of the account; it is a liability of the commercial bank.

Identify Whose Claim the Account Represents

A reliable classification method is to ask: Who owns the resource, or who is owed the money? Cash in a bank’s vault is controlled by the bank and is an asset. A balance in the bank’s account at the central bank is a claim of the commercial bank on the central bank, so it is also an asset of the commercial bank. By contrast, the balance recorded in a customer’s checking or savings account is owed by the commercial bank to that customer, so it is a liability.

This perspective also distinguishes two different banking relationships. In the central-bank account, the commercial bank is the creditor: the central bank owes the commercial bank the account balance. In a customer deposit account, the commercial bank is the debtor: it owes the customer the recorded balance. The word “balance” appears in both descriptions, but the identity of the account holder and the party that owes the balance determine its classification.

A bank balance sheet reports assets, liabilities, and equity. For a complete balance sheet, the accounting identity is:

\text{Assets}=\text{Liabilities}+\text{Equity}

Here, equity is the owners’ residual claim after liabilities are accounted for. This identity provides a check on a classification, but it does not make assets and liabilities interchangeable. If a customer deposit is listed as an asset of the bank, the balance sheet may fail to reconcile or may classify another account incorrectly.

A Short Justification: Why the Sides Differ

The classification follows from the meaning of each balance, not from the fact that both balances are measured in dollars. A bank’s vault cash is a resource available to the bank; the bank does not owe that same vault cash to a customer merely because a customer has an account. A central-bank reserve balance is an amount the central bank owes to the commercial bank. The commercial bank can therefore report that balance as a claim, and thus as an asset.

A customer deposit reverses the direction of the claim. The customer has a claim against the commercial bank for the amount recorded in the account. That obligation is a liability of the commercial bank. Accordingly, on the bank’s books, the same dollar amount cannot be classified as both the customer’s deposit liability and the bank’s reserve asset merely because the bank uses reserve assets in managing its payments.

\begin{aligned} \text{Bank's claim on central bank} &\longrightarrow \text{bank asset}\\ \text{Customer's claim on bank} &\longrightarrow \text{bank liability} \end{aligned}

The balance-sheet identity gives a related check. Assets are resources and claims held by the bank; liabilities and equity describe claims against the bank. Since reserves are resources or claims held by the bank, they enter the asset total. Since deposits are claims against the bank, they enter the liability total. This reasoning establishes the classification without assuming that every dollar of deposits is matched one-for-one by a dollar of reserves.

Worked Examples

Worked Example: Classifying and Reconciling a Bank’s Accounts

A hypothetical bank reports vault cash of $420,000, a central-bank reserve balance of $1,080,000, loans of $6,500,000, and securities of $2,000,000. It also reports customer deposits of $8,700,000 and borrowing from another financial institution of $500,000. Classify the accounts, find total reserves, and determine the equity required for the balance sheet to reconcile. Then calculate the reserve-to-deposit ratio.

Method. First classify each account by asking whether it is a resource or claim held by the bank, or an obligation owed by the bank. Then use the balance-sheet identity as a check.

Step 1: Classify the asset accounts. Vault cash and the central-bank balance are reserves. Loans and securities are also assets, but they are not reserves under the definition used here. Thus:

\text{Reserves}=\$420{,}000+\$1{,}080{,}000=\$1{,}500{,}000

Total assets are:

\$1{,}500{,}000+\$6{,}500{,}000+\$2{,}000{,}000=\$10{,}000{,}000

Step 2: Classify the liabilities. Customer deposits are liabilities because the bank owes those balances to customers. The borrowing is also a liability because the bank owes that amount to the other financial institution. Total liabilities are:

\$8{,}700{,}000+\$500{,}000=\$9{,}200{,}000

Step 3: Reconcile the balance sheet. Equity is the amount needed so that assets equal liabilities plus equity:

\text{Equity}=\$10{,}000{,}000-\$9{,}200{,}000=\$800{,}000

Step 4: Calculate the ratio. The reserve-to-deposit ratio is reserves divided by customer deposits:

\frac{\$1{,}500{,}000}{\$8{,}700{,}000}=0.172413\ldots

As a percentage, the ratio is 17.24%, rounded to two decimal places. The check is that assets of $10,000,000 equal liabilities of $9,200,000 plus equity of $800,000. A common mistake would be to add deposits to the bank’s assets because customers can access the money; the correction is to recognize that access reflects a claim against the bank, making deposits liabilities.

Worked Example: Reading Account Labels Carefully

A hypothetical bank’s report lists cash in its branches of $280,000, its account at the central bank of $920,000, household checking deposits of $4,600,000, household savings deposits of $3,200,000, loans of $6,300,000, and securities of $1,100,000. The bank also owes $500,000 on an overnight borrowing. Find reserves, total customer deposits, total assets, total liabilities, equity, and the reserve-to-deposit ratio.

Method. Separate the bank’s own cash and central-bank account from amounts owed to depositors. Do not classify an item by whether it is described as “money”; classify it by who holds the claim.

Step 1: Find reserves. Branch cash and the central-bank account are both bank assets included in reserves:

\$280{,}000+\$920{,}000=\$1{,}200{,}000

Step 2: Find customer deposits. Both checking and savings balances are amounts owed to customers:

\$4{,}600{,}000+\$3{,}200{,}000=\$7{,}800{,}000

Step 3: Find total assets. Add reserves, loans, and securities:

\$1{,}200{,}000+\$6{,}300{,}000+\$1{,}100{,}000=\$8{,}600{,}000

Step 4: Find total liabilities and equity. Liabilities include customer deposits and the overnight borrowing:

\$7{,}800{,}000+\$500{,}000=\$8{,}300{,}000

Therefore, equity is:

\$8{,}600{,}000-\$8{,}300{,}000=\$300{,}000

Step 5: Calculate the ratio.

\frac{\$1{,}200{,}000}{\$7{,}800{,}000} =0.153846\ldots =15.38\%

The balance-sheet check is $8,600,000 = $8,300,000 + $300,000. A tempting error is to count checking deposits as reserves because they are accessible for payments. Accessibility does not change whose claim the account represents: the deposits remain bank liabilities, and only the bank’s vault cash and central-bank balance are included in reserves here.

Worked Example: Comparing Two Banks’ Reserve Positions

Two hypothetical banks report the following amounts. Bank A has vault cash of $90,000, a central-bank balance of $610,000, and customer deposits of $2,800,000. Bank B has vault cash of $310,000, a central-bank balance of $390,000, and customer deposits of $3,100,000. Find each bank’s reserves and reserve-to-deposit ratio, then calculate the combined ratio for the two banks.

Method. Calculate each bank’s reserves by adding its two reserve components, then divide by that bank’s deposits. For the combined ratio, add the banks’ reserves and deposits before dividing.

Bank A. Its reserves are:

\$90{,}000+\$610{,}000=\$700{,}000

Its reserve-to-deposit ratio is:

\frac{\$700{,}000}{\$2{,}800{,}000}=0.25=25.00\%

Bank B. Its reserves are:

\$310{,}000+\$390{,}000=\$700{,}000

Its ratio is:

\frac{\$700{,}000}{\$3{,}100{,}000}=0.225806\ldots=22.58\%

Combined position. Total reserves are $700,000 + $700,000 = $1,400,000. Total deposits are $2,800,000 + $3,100,000 = $5,900,000. Therefore:

\frac{\$1{,}400{,}000}{\$5{,}900{,}000} =0.237288\ldots =23.73\%

The combined ratio is not the simple average of 25.00% and 22.58%, because the banks have different deposit totals. It is a deposit-weighted comparison, obtained directly from combined reserves divided by combined deposits. This descriptive ratio does not by itself specify a regulatory requirement or establish how much a bank may lend.

What a Reserve-to-Deposit Ratio Does—and Does Not—Say

A reserve-to-deposit ratio summarizes reserves relative to customer deposits for a stated bank or group of banks. Its calculation is straightforward:

\text{Reserve-to-deposit ratio} = \frac{\text{Vault cash}+\text{Central-bank reserve balance}} {\text{Customer deposits}}

Use consistent units in the numerator and denominator. If reserves are reported in thousands of dollars and deposits in dollars, convert one amount before dividing. The ratio is a comparison, not a new balance-sheet account. For example, a ratio of 20% means that the specified reserve total is one-fifth of the specified deposit total at that measurement point.

The ratio alone does not show that each customer’s deposit has a separately assigned reserve balance. Nor does it, without additional rules and assumptions, tell you a required reserve amount, a bank’s lending capacity, or the change in deposits following a change in reserves. Those questions require further concepts and conditions. For this topic, keep the accounting distinction clear: the bank’s reserves are assets; the deposits it owes are liabilities.

Common Classification Traps

Calling deposits assets because they are money in an account. Ask whose balance it is. A customer’s account balance is a claim on the bank, so it is a bank liability.
Calling a central-bank reserve balance a liability of the commercial bank. The commercial bank owns the claim on the central bank, so that balance is an asset of the commercial bank.
Treating every bank asset as a reserve. Loans and securities are assets, but they are not vault cash or central-bank reserve balances under the definition used here.
Adding reserves to deposits when calculating the ratio. The ratio divides reserves by deposits; deposits are not another reserve component.
Taking an unweighted average of bank ratios. For a combined ratio, add the reserves, add the deposits, and then divide.

These distinctions are aligned with the SOA VEE Economics (Validation by Educational Experience) syllabus because understanding the monetary system requires correctly identifying the claims and resources recorded by banks.

Key takeaway: Classify each balance from the bank’s point of view. Vault cash and a bank’s claim on the central bank are assets. A customer’s claim on the bank—whether checking or savings—is a liability. The reserve-to-deposit ratio compares these categories; it does not make them the same kind of account.

Check Your Understanding

For each problem, classify the balances before calculating. Ratios should be rounded to two decimal places.

A hypothetical bank reports vault cash of $150,000, a central-bank balance of $450,000, customer deposits of $2,400,000, and loans of $3,000,000. Find reserves and the reserve-to-deposit ratio. (Answer: reserves = $600,000; ratio = 25.00%)
A bank has checking deposits of $1,750,000 and savings deposits of $2,250,000. Explain how the total is classified on the bank’s balance sheet and calculate it. (Answer: customer-deposit liability = $4,000,000)
A bank lists vault cash of $75,000, a central-bank reserve balance of $525,000, loans of $4,200,000, customer deposits of $3,800,000, and other borrowing of $600,000. Find total assets, total liabilities, and the equity needed to reconcile the balance sheet. (Answer: assets = $4,800,000; liabilities = $4,400,000; equity = $400,000)
Bank C has reserves of $360,000 and deposits of $1,200,000. Bank D has reserves of $840,000 and deposits of $4,800,000. Calculate each ratio and their combined ratio. (Answer: Bank C = 30.00%; Bank D = 17.50%; combined = 20.00%)
A report shows that a bank has $240,000 in vault cash, $960,000 at the central bank, $5,000,000 in customer deposits, and $700,000 in securities. A candidate reports reserves of $6,900,000 by adding every listed amount. Identify the error and give the correct reserves and reserve-to-deposit ratio. (Answer: securities are an asset but not a reserve; reserves = $1,200,000; ratio = 24.00%)

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