Why Interbank Payments Change Two Banks’ Balance Sheets
When a customer pays someone who banks elsewhere, two kinds of balances are involved. The payer’s bank reduces a customer deposit, which is a liability of that bank. To settle the payment with the other bank, it also transfers a reserve balance, an asset used by banks to make settlement payments. The receiving bank records the customer’s deposit and receives the corresponding reserves.
The customer does not send the bank’s reserves to the recipient. The customer’s payment instruction causes banks to adjust their customer accounts and, as settlement occurs, to transfer the settlement asset between banks. This distinction is essential for reading paired bank balance sheets: deposits belong on the liability side, while reserves belong on the asset side.
The Basic Balance-Sheet Entries
First consider a single payment of \(P\) dollars from a customer at Bank A to a customer at Bank B. Assume both banks record the customer-account changes and final settlement together, the payment is completed in full, and there are no fees, interest adjustments, or other transactions. Bank A reduces the payer’s deposit and transfers \(P\) of reserves. Bank B receives \(P\) of reserves and increases the recipient’s deposit.
Each bank’s balance sheet remains balanced. At Bank A, assets fall by \(P\) and liabilities fall by \(P\). At Bank B, assets rise by \(P\) and liabilities rise by \(P\). The two-bank totals also provide a useful check: the payment redistributes reserves between banks and deposits between customers, but does not by itself change the combined reserve total or the combined deposit total.
This result describes the payment itself, not any separate event such as a cash withdrawal, a loan, or a fee. Those transactions would require their own entries. The payment does not create new reserves for the banking system: one bank’s reserve asset decreases by the amount that the other bank’s reserve asset increases.
Why the Entries Balance
A bank’s balance sheet must satisfy assets equal liabilities plus capital. For the payment, assume capital does not change. Let \(R\) denote reserves and \(D\) customer deposits. At Bank A, the reserve asset and deposit liability both decline by the same amount. At Bank B, both rise by the same amount. Thus the change in assets equals the change in liabilities at each bank.
The equality explains why the entries must be paired. Reducing the payer’s deposit without accounting for the settlement obligation would leave the bank’s records incomplete; recording a reserve transfer without the matching customer-account entry would also fail to describe the payment. In actual payment arrangements, clearing and settlement may occur at different times, so temporary clearing accounts can appear between the two events.
Worked Example: One Customer Pays Across Banks
Assume a hypothetical payment of $24,000 from a customer at Bank A to a customer at Bank B settles immediately. There are no fees or other transactions. Initially, Bank A has $120,000 of reserves, $480,000 of loans, $550,000 of deposits, and $50,000 of capital. Bank B has $80,000 of reserves, $320,000 of loans, $370,000 of deposits, and $30,000 of capital. Find each bank’s balances after settlement.
Method. Apply the payment entries to reserves and deposits only. Loans and capital do not change under the stated assumptions.
Bank A. Reserves fall by $24,000: $120,000 − $24,000 = $96,000. Deposits fall by the same amount: $550,000 − $24,000 = $526,000. Loans remain $480,000 and capital remains $50,000. Its assets are $96,000 + $480,000 = $576,000; its liabilities plus capital are $526,000 + $50,000 = $576,000.
Bank B. Reserves rise by $24,000: $80,000 + $24,000 = $104,000. Deposits rise by the same amount: $370,000 + $24,000 = $394,000. Loans remain $320,000 and capital remains $30,000. Its assets are $104,000 + $320,000 = $424,000; its liabilities plus capital are $394,000 + $30,000 = $424,000.
Check. Combined reserves are $120,000 + $80,000 = $200,000 before settlement and $96,000 + $104,000 = $200,000 afterward. Combined deposits are $920,000 both before and after. The common mistake is to subtract the payment from Bank A’s reserves but fail to add it to Bank B’s reserves; that would incorrectly reduce total reserves by $24,000.
Net Settlement of Offsetting Payments
Payment systems may settle multiple instructions individually or offset obligations and settle only the net amount. Suppose customers at Bank A send payments totaling \(x\) to Bank B, while customers at Bank B send payments totaling \(y\) to Bank A. If the system nets these obligations and \(x>y\), Bank A transfers \(x-y\) of reserves to Bank B.
The net transfer determines the change in each bank’s total reserves. The customer-account changes still reflect all the relevant instructions: Bank A’s deposits decline by \(x\) and increase by \(y\), for a net decline of \(x-y\); Bank B’s deposits increase by \(x\) and decline by \(y\), for a net increase of \(x-y\). This netting description assumes the instructions are valid and the settlement arrangement legally discharges the offset obligations. It does not mean that each customer’s individual payment disappears from the payment records.
Worked Example: Offset Payments and Net Reserve Settlement
Assume customers at Bank A send $18,000 to customers at Bank B, and customers at Bank B send $11,000 to customers at Bank A. The clearing arrangement nets these payments before settlement. Initially, Bank A has $90,000 of reserves, $210,000 of loans, $270,000 of deposits, and $30,000 of capital. Bank B has $55,000 of reserves, $145,000 of loans, $180,000 of deposits, and $20,000 of capital. There are no other transactions.
Method. Calculate the net direction and amount first, then apply that amount to each bank’s reserves and aggregate deposits.
The net obligation is $18,000 − $11,000 = $7,000 from Bank A to Bank B. Bank A’s reserves become $90,000 − $7,000 = $83,000, and its deposits become $270,000 − $7,000 = $263,000. Its assets are $83,000 + $210,000 = $293,000, and liabilities plus capital are $263,000 + $30,000 = $293,000.
Bank B’s reserves become $55,000 + $7,000 = $62,000, and its deposits become $180,000 + $7,000 = $187,000. Its assets are $62,000 + $145,000 = $207,000, and liabilities plus capital are $187,000 + $20,000 = $207,000.
Check. Combined reserves remain $90,000 + $55,000 = $145,000, and combined deposits remain $270,000 + $180,000 = $450,000. The common mistake is to transfer the gross $18,000 from A to B and ignore the $11,000 moving in the opposite direction. That would misstate the net reserve transfer by $11,000.
When Clearing and Settlement Occur at Different Times
The simple entries above treat the customer-account changes and reserve settlement as simultaneous. In a system where the recipient is credited before the reserve transfer is final, the banks may temporarily record clearing claims or obligations. The following example assumes both customer accounts are updated before final settlement: Bank A has debited its payer, and Bank B has credited its recipient. Bank A therefore records a clearing payable; Bank B records a clearing receivable. These temporary balances are not customer deposits or reserves.
Worked Example: A Payment with Temporary Clearing Balances
Assume a hypothetical $12,500 payment from a Bank A customer to a Bank B customer. Before the payment, Bank A has $70,000 of reserves, $130,000 of loans, $180,000 of deposits, and $20,000 of capital. Bank B has $40,000 of reserves, $110,000 of loans, $135,000 of deposits, and $15,000 of capital. Both customer-account entries occur before final settlement; there are no fees or other transactions.
Method. First record the customer debit and credit with a payable and receivable. Then settle by reducing the payable and receivable while transferring reserves.
Before final settlement, Bank A has reserves of $70,000 and loans of $130,000, for total assets of $200,000. Deposits fall to $180,000 − $12,500 = $167,500. The bank also records a $12,500 clearing payable. Liabilities plus capital are $167,500 + $12,500 + $20,000 = $200,000.
Before final settlement, Bank B has reserves of $40,000 and loans of $110,000, plus a $12,500 clearing receivable, for total assets of $162,500. Deposits rise to $135,000 + $12,500 = $147,500. Liabilities plus capital are $147,500 + $15,000 = $162,500.
At settlement, Bank A transfers $12,500 of reserves and clears its payable. Reserves become $70,000 − $12,500 = $57,500, and the payable becomes zero. Assets are $57,500 + $130,000 = $187,500; deposits plus capital are $167,500 + $20,000 = $187,500.
At settlement, Bank B receives $12,500 of reserves and clears its receivable. Reserves become $40,000 + $12,500 = $52,500, and the receivable becomes zero. Assets are $52,500 + $110,000 = $162,500; deposits plus capital are $147,500 + $15,000 = $162,500.
Check. After settlement, combined reserves are $57,500 + $52,500 = $110,000, the same as the initial $70,000 + $40,000. Combined deposits are $167,500 + $147,500 = $315,000, the same as the initial $180,000 + $135,000. The temporary payable and receivable cancel when the two banks are considered together.
Common Mistakes and Why the Distinction Matters
- Treating reserves as the customer’s money. The customer owns a deposit claim against their bank. The reserve balance is an asset of the bank used to settle with another bank.
- Changing only one bank’s reserves. A reserve transfer between two banks reduces one bank’s balance and increases the other’s by the same amount. It does not, by itself, change total reserves.
- Putting deposits on the asset side. A customer deposit is a liability of the bank. When the bank credits a recipient’s deposit, its liabilities increase.
- Confusing gross payment instructions with net settlement. With offsetting payments, calculate both directions before determining the net reserve transfer.
- Ignoring settlement timing. If customer accounts are updated before reserve settlement, a clearing payable or receivable may be needed to keep the interim balance sheet complete.
For a professional reviewing bank accounts or payment flows, the paired-bank method makes it possible to distinguish a transfer from a change in the banking system’s totals. It also prevents an incorrect inference that a customer payment creates deposits in the aggregate. In the model used here, one customer’s deposit decreases as another customer’s deposit increases; the reserve asset changes location between banks rather than being created by the payment.
Check Your Understanding
For each problem, assume no fees or unrelated transactions unless stated. Track the customer deposits separately from bank reserves.
- A customer at Bank M pays $8,400 to a customer at Bank N, and the payment settles immediately. State the reserve and deposit change at each bank and the change in combined reserves. (Answer: Bank M reserves and deposits each fall by $8,400; Bank N reserves and deposits each rise by $8,400; combined reserves change by $0.)
- Bank A begins with $64,000 of reserves and $190,000 of deposits; Bank B begins with $45,000 of reserves and $130,000 of deposits. Customers send $27,000 from A to B and $9,000 from B to A; obligations are netted before settlement. Find the net transfer and the ending reserves and deposits. (Answer: $18,000 from A to B; A ends with $46,000 reserves and $172,000 deposits; B ends with $63,000 reserves and $148,000 deposits.)
- Payment instructions total $14,200 and $6,800 from Bank R to Bank S, and $5,500 from Bank S to Bank R. If they are netted, how much reserve settlement occurs and in which direction? If R initially has $72,000 of reserves and S has $31,000, find their ending reserves. (Answer: $15,500 from R to S; R ends with $56,500 and S with $46,500.)
- A $3,600 payment from Bank C to Bank D is credited to the recipient before final settlement. State the temporary clearing account at each bank and the reserve changes when settlement occurs. (Answer: Bank C records a $3,600 clearing payable and Bank D a $3,600 clearing receivable; at settlement C’s reserves fall by $3,600 and D’s rise by $3,600, and both clearing balances are removed.)
- Bank E has $50,000 of reserves and $120,000 of deposits; Bank F has $40,000 of reserves and $100,000 of deposits. A customer at E pays $12,000 to a customer at F, while one customer at F pays another customer at F $4,000. Find each bank’s ending reserves and aggregate deposits. (Answer: E ends with $38,000 of reserves and $108,000 of deposits; F ends with $52,000 of reserves and $112,000 of deposits; aggregate deposits remain $220,000.)