Banking, Credit & Financial Stability

CASA Ratio Explained: When Cheap Deposits Stop Being Cheap

CA Nikhil Gupta·May 2026·4 min readBanking, Credit & Financial Stability

CASA Ratio Explained: When Cheap Deposits Stop Being Cheap. Understand the cash flow, ratio, public impact, warning signs, practical example and official data sources...

What the casa ratio reveals about funding mix and why current and savings accounts are not permanently cheap.

Current Context

RBI data for 31 March 2026 showed bank credit growth of 16% and deposit growth of 13.4%, with advances of about ₹219 lakh crore and deposits of about ₹267.8 lakh crore. The December 2025 Financial Stability Report placed scheduled commercial banks’ gross NPA ratio at 2.1% in September 2025 and projected 1.9% by March 2027 under its baseline scenario.

Measurement date: 25 June 2026. Figures should be read with the cited official series and reporting period.

Quick View

Core question

What the casa ratio reveals about funding mix and why current and savings accounts are not permanently cheap.

Primary ratio

CASA ratio

Practical lens

Follow cash, liability, execution and outcome.

Main caution

Falling savings balances

How It Works

  • CASA deposits generally pay lower explicit interest than term deposits.
  • Acquisition, technology, branch and transaction costs mean CASA is not free.
  • When customers shift to term deposits or market products, the CASA ratio and margin advantage can fall.

Detailed Analysis

The central question is what the CASA ratio reveals about funding mix and why current and savings accounts are not permanently cheap. A useful answer begins with the accounting identity and then follows the cash flow. Headlines often describe a policy, liability or ratio without showing who funds it, who receives the benefit and what changes if assumptions fail.

The first mechanism is casa deposits generally pay lower explicit interest than term deposits. This is the starting point because the bank balance sheet records stocks and flows differently. A liability can remain invisible in the current cash deficit, while a payment can reduce cash without improving the underlying position.

The second mechanism is acquisition, technology, branch and transaction costs mean casa is not free. The timing matters. Budget estimates, revised estimates and actuals can diverge; similarly, a bank’s quarter-end ratio can differ from its average position during the quarter.

The third mechanism is when customers shift to term deposits or market products, the casa ratio and margin advantage can fall. This is why readers should examine incentives and behaviour, not only compliance with a numerical ceiling.

Track CASA ratio, cost of deposits, savings rate, term-deposit mix, customer acquisition cost, and deposit churn. Read the level, direction, five-year range, denominator and data date. A ratio can improve because the numerator strengthened or because the denominator expanded; those are not the same economic story.

The main stakeholders are banks, depositors, shareholders, fintech partners, and borrowers. Their interests can conflict. A subsidy may help one group while raising taxes, tariffs or borrowing costs for another. A profitable lending product may help shareholders while increasing future household stress.

A strong assessment separates liquidity, solvency and service delivery. Liquidity asks whether cash is available now. Solvency asks whether assets and future revenue can cover liabilities. Service delivery asks whether the spending or lending produces the intended economic result.

The measurement date must sit beside every current number. State accounts are published with lags and revisions; bank ratios can move rapidly with growth, write-offs, market yields and funding conditions. Comparisons should use the same period and definition.

The most important warning signals are falling savings balances, reward-led acquisition, concentrated corporate current accounts, and term-deposit migration. One signal may be manageable. Several moving together can indicate that the apparent benefit is being financed by weaker future cash flow, rising concentration or reduced flexibility.

Finin2min’s decision rule is simple: identify the claim, find the cash source, calculate the ratio, test a downside scenario and record the evidence that would change the conclusion. This method is more useful than ranking governments or banks from one headline number.

Key Formula

CASA ratio = current and savings deposits ÷ total deposits

Use the same accounting perimeter and date for every component. State whether the ratio is a stock, flow, annual average or period-end measure.

Indicators to Track

CASA ratioTrack the level, direction, denominator, date and peer range.
cost of depositsTrack the level, direction, denominator, date and peer range.
savings rateTrack the level, direction, denominator, date and peer range.
term-deposit mixTrack the level, direction, denominator, date and peer range.
customer acquisition costTrack the level, direction, denominator, date and peer range.
deposit churnTrack the level, direction, denominator, date and peer range.

Practical Example

A bank can report a high CASA ratio yet face rising effective cost if it spends heavily on rewards, branches and digital acquisition. The conclusion should change if the funding source, beneficiary count, default rate, maturity or execution assumption changes.

Stakeholder Impact

StakeholderWhat to examine
banksBenefit, cost or risk depends on the funding route, contract and time horizon.
depositorsBenefit, cost or risk depends on the funding route, contract and time horizon.
shareholdersBenefit, cost or risk depends on the funding route, contract and time horizon.
fintech partnersBenefit, cost or risk depends on the funding route, contract and time horizon.
borrowersBenefit, cost or risk depends on the funding route, contract and time horizon.

Warning Signs

  • falling savings balances
  • reward-led acquisition
  • concentrated corporate current accounts
  • term-deposit migration

Decision Checklist

  1. Confirm the legal entity, reporting perimeter and accounting period.
  2. Download the official budget, audit report, RBI return or regulatory disclosure.
  3. Calculate the primary ratio using the same numerator and denominator period.
  4. Compare budget estimates with revised estimates and actuals, or quarter-end with average balance.
  5. Add guarantees, write-offs, restructuring, arrears or off-balance-sheet exposure where relevant.
  6. Run a downside scenario for revenue, interest rates, defaults, withdrawals or execution delays.
  7. Record the practical impact on citizens, borrowers, depositors or investors.

Finin2min Takeaway

CASA Ratio Explained: When Cheap Deposits Stop Being Cheap becomes useful only when the headline is converted into a funding source, measurable ratio, downside scenario and real effect on services, cash flow or financial stability.

Frequently Asked Questions

What is the first ratio to calculate? â–¼
Begin with CASA ratio and then test whether the denominator and measurement date are comparable.
Can one ratio prove safety or efficiency? â–¼
No. Combine funding, cash flow, liabilities, execution and outcome indicators.
How often should the figures be reviewed? â–¼
Use the reporting frequency of the official source and reassess after a budget, audit, RBI release or material policy event.
What is the biggest interpretation mistake? â–¼
Treating an accounting improvement as a cash recovery, service improvement or permanent reduction in risk.