Disposable income
What remains from monthly income after mandatory expenses — taxes and loan repayments — are met; essential living costs and discretionary spending are paid out of it, and what is left is savings.
In plain language
Budgeting only works if you know which expenses you actually control. The workbook builds its budgeting process around one key checkpoint: disposable income.
It sits between two things you largely cannot choose and two things you can. Taxes and loan repayments come first and have to be met regardless. What remains after those mandatory expenses is disposable income — and it is only from that remaining pool that essential living costs and discretionary spending are paid.
How it works
The workbook sets out budgeting as a four-step sequence, and disposable income is the product of step two:
- List regular income expected in the month — the income available to meet current and future needs.
- List mandatory expenses — taxes, loan repayments — which must be met first out of that income. What remains is the disposable income.
- Meet essential living expenses out of disposable income next — housing, food, transportation, health and other necessary costs. These cannot be eliminated, though they can often be reduced.
- Discretionary expenses — entertainment and recreation — come last.
Whatever remains after all four steps is savings. The workbook is explicit that ad hoc or irregular savings will not build the corpus a goal requires — there should be a target savings amount each period. Since income is harder to expand (limited by skills and time available for additional work), controlling expenses is the more effective lever — and discretionary expenses are the category most easily cut back or eliminated when savings targets are not being met.
A worked example
Mr Verma earns Rs 90,000 a month.
| Step | Category | Amount | Running balance |
|---|---|---|---|
| 1 | Regular income | Rs 90,000 | Rs 90,000 |
| 2 | Mandatory expenses (tax deducted at source, home loan EMI) | Rs 28,000 | Disposable income = Rs 62,000 |
| 3 | Essential living expenses (housing maintenance, groceries, transport, health) | Rs 32,000 | Rs 30,000 remaining |
| 4 | Discretionary expenses (dining out, entertainment) | Rs 14,000 | Rs 16,000 remaining |
| — | Savings | — | Rs 16,000 |
His disposable income is Rs 62,000 — not his gross salary of Rs 90,000, and not the Rs 30,000 left after essential costs either. It is specifically the amount left once the mandatory items (tax and EMI) are met.
If Mr Verma's retirement goal needs Rs 20,000 a month in savings rather than Rs 16,000, the workbook's guidance points him first to the discretionary Rs 14,000 — cutting Rs 4,000 of dining and entertainment — rather than to his essential living costs or to chasing extra income, which is harder to expand reliably.
Why NISM asks about it
Chapter 3 (Retirement Planning Process), section 3.1.2 (Budget to Realize Savings), defines disposable income as the second step of the four-step budgeting sequence, immediately before essential and discretionary expenses. Expect a question on the order of the sequence — mandatory expenses first, essential next, discretionary last — and one asking what disposable income actually is: income after mandatory expenses, not income after all expenses.
Common exam traps
- Disposable income is after mandatory expenses only — taxes and loan repayments — not after essential living costs as well. A common wrong answer subtracts rent or groceries too early.
- Savings is what is left after all four steps, not the same thing as disposable income — disposable income is an intermediate figure, savings is the final one.
- Discretionary expenses, not essential ones, are the primary lever for raising savings — essential costs can be reduced somewhat, but the workbook singles out discretionary spending as what "can be cut back or even eliminated" to hit a savings target.
- Expanding income is limited by skills and available time — the workbook treats controlling expenses as the more reliable route to higher savings, not earning more.
- Do not confuse this budgeting-process definition with the macroeconomic sense of "disposable income" (income after direct taxes, at a national-accounts level) — this page teaches the household-budget version the workbook itself uses.
Check yourself
1.In the budgeting process, what is disposable income?
- a)Income left after meeting all expenses including discretionary ones
- b)Income left after meeting mandatory expenses such as taxes and loan repayments
- c)Total regular income expected in the month
- d)Income left after meeting essential living expenses
Show the answer
Answer: (b) Income left after meeting mandatory expenses such as taxes and loan repayments
The budgeting sequence runs in a fixed order: list regular income → subtract mandatory expenses that have to be met like taxes, loan repayments. What remains is the DISPOSABLE INCOME.
Essential living expenses — housing, food, transportation, health — come out of disposable income next, then discretionary expenses on entertainment and recreation.
Savings is what remains from the income after meeting all these expenses — which is option (a), a different thing entirely.
The order matters practically: mandatory expenses cannot be negotiated, essential ones cannot be eliminated but can be reduced, and discretionary ones can be cut back or even eliminated.
2.What is the correct sequence of steps in the budgeting process described in the workbook?
- a)List discretionary expenses → list essential living expenses → list mandatory expenses → list regular income
- b)List regular income → meet essential living expenses → meet mandatory expenses → meet discretionary expenses
- c)List regular income → meet discretionary expenses → meet essential living expenses → pay taxes and loan repayments
- d)List regular income expected in the month → meet mandatory expenses such as taxes and loan repayments → meet essential living expenses out of disposable income → meet discretionary expenses; savings is what remains
Show the answer
Answer: (d) List regular income expected in the month → meet mandatory expenses such as taxes and loan repayments → meet essential living expenses out of disposable income → meet discretionary expenses; savings is what remains
The workbook's steps:
- List the regular income that is expected in the month.
- List the mandatory expenses that have to be met like taxes, loan repayments. These have to be first met out of the available income. What remains is the disposable income.
- The essential living expenses have to be met out of disposable income next, covering housing, food, transportation, health and other necessary expenses.
- Discretionary expenses are the last category of expenses and includes expenses on entertainment and recreation.
Savings is what remains from the income after meeting all these expenses. So option D is correct.
Why the others are wrong:
- Option A runs the process backwards.
- Option B puts essential living expenses before mandatory ones. Mandatory expenses come first, and essentials are paid from the disposable income left after them.
- Option C puts discretionary spending ahead of necessities and leaves taxes and loans until last.
The workbook also notes that controlling expenses is a more effective way to generate savings than expanding income, and that discretionary expenses are in the category of expenses that can be cut back or even eliminated.
Where this is taught
- Series XVII · Chapter 3: Retirement Planning Processintroduced here
- Series X-A · Chapter 3: Cash Flow Management and Budgetingintroduced here
Related terms
- Savings ratioSavings relative to income, which the workbook says should ideally rise over the life cycle — read alongside a falling expense ratio and a debt-to-income ratio that peaks around a big loan.
- Financial planningThe process of estimating what a person will need money for across their lifetime and building an investment plan to meet each of those needs — savings with a purpose attached.
- BudgetingListing and itemising a household's income and expenses — mandatory, essential and discretionary — to keep spending within income and generate a targeted amount of savings for goals.