Debt Mutual Fund SIPs vs RDs: The After-Tax Numbers Still Favor Debt Funds

Ever since debt mutual funds got a new tax treatment using the income tax slab rates, investors have been wondering if the strategic benefits of indexation and holding-period-defined flat tax rates have been completely nullified.

To remove that decision hurdle, investors need a complete breakdown of what is happening to their money in a debt mutual fund compared with a bank recurring deposit (RD). This single hurdle is likely fueled by many misaligned beliefs and assumptions that can cost the investor their hard-earned money.

A comparison between debt mutual funds and recurring deposit accounts, on taxable income, maturity value, TDS treatment, risk tolerance, and investor psychology, will be an eye-opener and a helper in choosing the correct instrument of growth.

Misconception 1: “Debt Funds and RDs have the same Taxable Base”

For a debt mutual fund, the gains earned on the investment form the taxable base, and that amount is determined by the difference between the unit purchase cost and redemption value.

For a recurring fixed deposit, the interest earned on the principal is considered the taxable base.

Assuming a monthly investment of ₹20,000 and an 8% annual interest rate and average annual investment return. The total investment made in 5 years in both scenarios will be ₹12 lakh, but the gains generated differ from the interest accumulated.

The Maturity Value in a Recurring Deposit account is calculated using this industry-standard formula:

Maturity value (M) of a Recurring Deposit
= Monthly Deposit (R) × Future Value Interest Factor of an Annuity Due (FVIFA-due)
= Monthly Deposit (R) × [(1 + quarterly interest rate i) ^ no. of quarters – 1] / [1 – (1 + quarterly interest rate i) ^ (–1/3)]

A quarterly interest rate and a quarterly time period are applied in the formula because Indian banks generally use a quarterly compounding cycle, which tells how many times in a year the compounding takes place. In each quarter cycle, the interest is calculated on the total RD value, and that interest then gets folded into the existing RD value at the end of that quarter. Here, the quarterly interest rate is 2% and the number of quarters is 20. The multiplier output is 73.8546.

The Total Portfolio Value (or Future Value, FV) of a SIP investment is calculated using this Annuity formula:

Portfolio Value of a SIP investment
= Monthly Investment (FV) × Future Value Interest Factor of an Annuity Due (FVIFA-due) Multiplier
= Monthly Investment (FV) × [(1 + monthly interest rate i) ^ no. of months – 1] / monthly interest rate i × (1 + monthly interest rate i)

Conversely, a SIP investment uses a monthly compounding cycle, where the compounding effect is applied to the total investment every month. Here, the monthly interest rate is 0.67% and the number of months is 60. The multiplier output is 74.0463.

The compounding effect on its own produces the difference in the taxable amount between the two money instruments. Since the SIP investment compounds more times in a year, it also produces more accumulation than an RD account and a larger taxable base. Here, a 5-year growth with a ₹20,000 monthly input produced a difference of ₹3,834.

It should be noted that both the taxable base outputs produced here can differ from an actual case. The return rates used in a debt mutual fund are assumed averages based on past performance of the fund, and hence the average and year-to-year return can vary significantly from an advertised fund return rate of 8%. The 8% interest rate assumption for RDs or FDs is guaranteed by the bank. Even the RD Maturity Value calculation is an industry standard that may differ slightly between banks and is not publicly disclosed.

Misconception 2: “TDS Is Just Tax Paid Early, So My Final Corpus Will Be the Same”

Money in a recurring deposit is also subject to another rule that is not applicable to a SIP investment corpus. Since interest from a Recurring Deposit is classified as Interest Income, TDS is applicable on it. That means that if the annual RD interest exceeds ₹50,000 for non-senior citizens in any particular year, then 10% of that interest is deducted before it is credited to the RD account, according to Section 194A of the Income Tax Act, 1961. That deducted amount can no longer compound inside the RD.

Conversely, SIP investments produce Capital Gains, on which tax is payable only when fund units are redeemed and not before. This is the tax-deferral benefit of SIPs over a Recurring Deposit.

After TDS, the rest of the tax that is payable, based on the income slab rates, is cleared before the tax filing is done, from the person's own savings account and not deducted from their RD account.

Taking our RD amount example, the ₹20,000 monthly input grows, and 10% TDS gets deducted from it during years 4 and 5. This amount can no longer compound due to TDS.

The year-end RD corpus value is calculated using the same recurring deposit Maturity value (M) formula. But after the TDS is deducted in any previous year, the current year’s interest is generated on two principal values:

• The year-end corpus of the previous year, which is now treated as a one-time lump sum input for the current year, and
• The continuing monthly installments of the current year.

The maturity value for RD from the one-time lump sum is treated as a simple Fixed Deposit input and calculated using this formula:

Maturity value (M) of a Fixed Deposit
= Deposit (P) × Compound Interest Factor
= Deposit (P) × (1 + quarterly interest rate i) ^ no. of quarters

The monthly instalments that continue in years 4 and 5 are treated as starting from the year after the TDS deduction and use the maturity value formula of a recurring deposit.

The final accumulated corpus value has shrunk even lower with TDS applied on a Recurring Deposit, and is still lower compared to a Debt mutual fund. This clearly shows that the portfolio grows more in a debt mutual fund using SIP investments.

In reality, debt funds also offer a higher return rate of 10% or more, in general, which produces greater returns.

Debt Funds vs RDs: Which Is Better for Different Investor Types?

Conservative Investor:

A conservative investor cares about predictable earnings first.

Best Fit — Recurring Deposit (RD)

Recurring Deposits offer a predictable interest rate guaranteed by the bank, which is protected from market fluctuations. This certainty of returns can be an attractive feature.

Even though SIPs invested in a Debt Mutual Fund are considered safe investments in general, the actual intensity of fluctuations in the fund NAV depends heavily on the fund's duration, credit quality, and portfolio composition. The fact that the advertised return rate is an average that can vary wildly from the real year-to-year rate, causing bad years in return, can be an important factor of consideration for a conservative investor.

Returns-Conscious Investor:

Such investors care about getting the best return for their investment.

Best Fit — Depends on your return assumption and risk tolerance

Recurring Deposits, although predictable, usually offer low interest rates of around 8% compared to most debt mutual funds, offering around 10% to 12%. Adjusting for inflation of about 4%, RDs seem to grow even slower. This can be a major deciding factor against RDs.

Investors use the simple Rule of 72 to check how fast their money will double, based on the return.

Years to double ~ 72 / Annual Return Rate

For example, at 10% returns, the investment roughly doubles every 7.2 years; at 12%, it takes about 6 years; and at 15%, it takes around 4.8 years. Even though this rule simplifies the choice, risk tolerance must also be taken into account, as it increases with the return expectation of a debt fund.

Tax-Conscious Investor:

Best Fit — Debt Mutual Fund

Such investors want to control when a tax event happens in their investment. Even at an identical 8% return rate, a debt fund does grow faster than a recurring deposit, even though the income tax slab rates applicable are the same. An investor in a higher tax bracket of, say, 30% may choose either method of growing their wealth.

What Risks Are You Taking?

For many Indian investors, a “safe investment” means a Fixed Deposit / Recurring Deposit or gold. Fixed deposits have always offered a predictable interest and maturity value, while gold has always been used as a store of value and a hedge in uncertain times.

But neither financial instrument is protected from Interest-rate risk or Credit risk.

• Interest-rate risk in mutual funds arises when changes in market interest rates cause the value of bonds held by a debt mutual fund to change, further leading to a change in the fund NAV. Generally, a rise in interest rates causes the bond price and the connected mutual fund NAV to fall, and vice versa.

  An FD/RD investor who is used to seeing a growing interest accumulating with the original principal in their account would be shocked by the possibility of their portfolio value falling below their original investment. RDs therefore offer greater certainty of value than debt funds.

  But if an investor wishes for a higher-return instrument, then a low-duration debt mutual fund might be a safe option that also gives greater returns than an FD/RD. The low duration of the fund specifically makes it less susceptible to interest rate changes.

• Credit/Default risk in mutual funds arises when the issued bonds held by a debt mutual fund cannot pay back the interest or principal owed to the fund.

  Debt mutual funds are exposed to credit risk. But even among them, funds with high-quality bonds, especially government bonds, are still a safe choice to start investing. Gilt funds are a great example.

  Bank Deposit Default risk is a situation where the bank may fail to pay account holders when their fixed or recurring deposits mature or when they withdraw funds.

  Eligible bank deposits have DICGC (Deposit Insurance and Credit Guarantee Corporation) protection of up to ₹5 lakh per depositor, per bank, including both principal and interest. So if your bank collapses, DICGC pays you back, but only up to the threshold. Everything above this ₹5 lakh may be returned by the bank, but that is not guaranteed.

  On the other hand, debt funds have assets spread across bonds and issuers. This diversification reduces the impact of any one issuer defaulting. Still, it does not remove the risk completely.

The SEBI-mandated Risk-o-meter is a framework to quickly assess the overall risk level of a mutual fund scheme. It considers interest-rate risk, credit risk, and liquidity risk. AMCs are required to disclose this information along with the fund scheme. Investors can check the risk-o-meter before deciding on any mutual fund.

Why SIPfund?

Moving from the predictability of an RD to a market-linked debt fund can feel uncomfortable. You may be willing to accept some fluctuation for the potential benefits of a mutual fund, but you still want to know what is happening to your money.

• The SIPfund app brings all your mutual funds onto a single platform so you can conveniently track your portfolio value, fund details, investment progress, and keep a close eye on negative fluctuations. SIPfund gives you access to all your funds, even those bought elsewhere.
• SIPfund’s advisory team also provides investment reviews for your portfolio so you can make safe decisions instead of reacting to market fluctuations.

Whichever way this comparison tips for you, SIPfund is a place to get a second opinion before you act. If you're moving into debt funds, our advisory team can help you pick the right duration and credit quality for your risk comfort. If you're staying with your RD, we can still help you check whether a low-duration debt fund might be worth testing with a small amount alongside it. Either way, you don't have to make this call alone.

What Next

If you're a Conservative Investor — predictability matters most to you. Before making a change, check the SEBI Risk-o-meter on any debt fund you're considering, or call our advisory team at 95133 55661 to see if a low-duration debt fund fits your comfort level.

If you're a Returns-Conscious Investor — start your SIP in a debt fund on the SIPfund App (iOS or Android), and pick a fund duration that matches your investment horizon.

If you're a Tax-Conscious Investor — you can also start your SIP in a debt fund on the SIPfund App to take advantage of tax deferral until redemption.

Not sure which profile fits you? Call our advisory team at 95133 55661, and we will help you decide in under 60 minutes. You can also reach us on WhatsApp.

<i>Disclaimer: The information provided in this article is for educational purposes only and does not constitute investment advice or a recommendation to buy or sell any mutual fund. Mutual Fund investments are subject to market risks; read all scheme-related documents carefully.</i>