Non-Permissible Income: How the 5% Purification Threshold Works

Most Shariah screens have a 5% rule you've probably heard about but maybe never used. The rule says: if a company's income from non-permissible sources exceeds 5% of total revenue, the stock fails. If it's under 5%, the stock can pass, but you have to purify your share of that non-permissible income by donating it to charity.

The mechanics of this are surprisingly concrete. It's one of the few places where Shariah screening translates into specific dollar amounts you owe out of each dividend. And it's one of the most-skipped obligations in Islamic investing because almost nobody actually runs the numbers.

Let me walk through what "non-permissible income" means, how the 5% threshold works, and how you calculate the purification amount per share.

What counts as non-permissible income

The concept is simpler than it sounds. Non-permissible income is any revenue or earnings that, if the company earned them on their own as a standalone business, would have disqualified the company from Shariah compliance. The big categories:

Interest income. This is the biggest one for most companies. Any interest earned on cash deposits, bonds, treasury bills, or intercompany loans counts. If Apple parks cash in a money market fund earning 5% interest, that interest is non-permissible.

Income from conventional insurance. If a company owns or operates a conventional insurance subsidiary (not takaful), the income from that subsidiary is non-permissible.

Income from conventional lending. A company that owns a consumer finance subsidiary generating interest-based loans creates non-permissible income even if the parent is a permissible manufacturer.

Income from alcohol, tobacco, pork, gambling, adult content. Even if these are minor product lines, the revenue counts. This is why hotel chains sometimes get flagged (mini-bar alcohol sales) and why airlines sometimes get flagged (duty-free sales).

Income from financial speculation. Trading gains from speculative derivatives can count under strict interpretations.

What doesn't count:

• Operating income from the core permissible business
• Dividends received from compliant subsidiaries
• Capital gains from permissible investments
• Foreign exchange gains from operational currency conversion

The 5% threshold logic

Scholars have long debated the right threshold for tolerable non-permissible income. Three positions:

Zero tolerance. Any non-permissible income makes the stock non-compliant. This position is theologically pure but practically impossible because virtually every public company has some cash holdings earning interest.

33% tolerance (aligned with the debt threshold). Some early scholars argued that if one-third is the limit for impermissible debt, it should also be the limit for impermissible income. This position has largely been abandoned because 33% felt too lenient for revenue.

5% tolerance. This became the consensus position in the 1990s among scholars working on the first Islamic indices. The reasoning: 5% is small enough to represent genuinely incidental activity, large enough to allow normal corporate cash management, and conveniently easy to compute from published financial statements.

Mufti Taqi Usmani and Sheikh Nizam Yaquby both signed off on the 5% figure for the early DJIM methodology, and it has stayed there ever since. AAOIFI Standard 21 uses 5%. S&P Shariah uses 5%. FTSE Yasaar uses 5%. MSCI Islamic uses 5%.

The formula

Non-permissible income ratio = (Interest income + other non-permissible revenue) / Total revenue

If this number exceeds 5%, the stock fails screening regardless of the debt and liquidity ratios. If it's at or below 5%, the stock can pass but requires purification.

The hard part is finding the numerator. Companies don't always break out "interest income" cleanly in their financial statements. You often have to dig into the cash flow statement, the other income line, and the segment disclosures to reconstruct the number.

FaithScreener does this automatically using pattern-matching across quarterly filings. We pull interest income from the income statement where disclosed, we estimate it from cash positions and market interest rates where not, and we add revenue from any non-core segments that fail the business activity screen.

Worked example: Apple

Let's do Apple's purification calculation for a hypothetical year.

Apple's fiscal 2024 results (approximate):
- Total revenue: 391 billion
- Interest income (reported in other income): approximately 2.9 billion
- No tobacco, alcohol, pork, gambling, insurance, or lending subsidiaries

Non-permissible income: roughly 2.9 billion
Non-permissible income ratio: 2.9 / 391 = 0.74%

Apple passes the 5% screen with enormous margin. But the purification obligation still applies.

Apple paid total dividends of approximately 15 billion in fiscal 2024. Apple has roughly 15.5 billion shares outstanding. Dividend per share: approximately 0.96 dollars.

Purification ratio = non-permissible income / total revenue = 0.74%

Purification per share = dividend per share times purification ratio = 0.96 times 0.0074 = 0.0071 dollars, or about 0.71 cents per share.

If you own 1,000 shares of Apple, your annual purification obligation is about 7 dollars and 10 cents. Tiny. But it's still an obligation.

Worked example: Nestlé

Nestlé (NESN.SW) is interesting because it has a complicated corporate structure with some minor non-permissible exposure.

Approximate Nestlé figures:
- Total revenue: approximately 93 billion CHF
- Interest income: approximately 600 million CHF
- Non-core investment income from corporate treasury: varies

Non-permissible income ratio: roughly 0.65%

Nestlé passes comfortably. Purification would be about 0.65% of dividends received.

Nestlé's debate in Islamic investing circles is never about the 5% screen. It's about the debt ratio under total-assets methodologies and occasionally about infant formula ethics (which is a separate conversation, not a Shariah screening question).

Worked example: Toyota

Toyota (7203.T) is fascinating because it has both a permissible business (auto manufacturing) and a gigantic non-permissible business (Toyota Financial Services). Let's see what happens.

Approximate Toyota figures (2024):
- Total revenue: approximately 45 trillion yen
- Toyota Financial Services revenue: approximately 3 trillion yen (rough estimate based on segment disclosures)

Non-permissible income ratio: 3 / 45 = 6.7%

Toyota fails the 5% screen by about 1.7 percentage points. This is in addition to failing the debt ratio. Toyota is non-compliant under every mainstream methodology partly because the financing arm generates more than 5% of consolidated revenue.

If Toyota decided to spin off Toyota Financial Services into a separately listed subsidiary, the remaining "Toyota Manufacturing" entity might actually become Shariah-compliant. Several scholars have discussed this hypothetical, and it's one of the reasons some analysts think structural changes at big auto makers could open up Islamic investor demand.

Worked example: Saudi Aramco

Saudi Aramco (2222.SR) has essentially no non-permissible income exposure.

Approximate Aramco figures:
- Total revenue: approximately 440 billion (2024)
- Interest income: approximately 3-5 billion

Non-permissible income ratio: roughly 1%

Aramco passes comfortably. Purification per share is minimal because Aramco's interest income is small relative to its oil revenue.

This is another reason Aramco is the cleanest Shariah pass in the mega-cap universe. Oil revenue is permissible, there's no financing arm of meaningful scale, the insurance book is tiny, and the cash position generates modest interest.

Worked example: Microsoft

Microsoft (MSFT) is similar to Apple but with a slightly larger cash-driven interest income line in recent years.

Approximate figures:
- Total revenue (fiscal 2024): approximately 245 billion
- Interest income: approximately 3.2 billion

Non-permissible income ratio: 1.3%

Passes comfortably. Purification per share on Microsoft dividends is slightly higher than Apple in percentage terms, but still tiny in absolute terms.

If you own 100 shares of Microsoft paying roughly 3 dollars per share in annual dividends, your purification obligation is about 3 dollars times 0.013 = 0.039 dollars per share, or about 3.9 cents per share. Total annual purification for 100 shares: 3.90 dollars.

Forgettable in dollar terms. Not forgettable in obligation terms.

Tesla: still growing into the screen

Tesla (TSLA) doesn't pay a dividend, so purification per share is zero on dividend grounds. But capital gains purification is a separate debate in Islamic finance, and some scholars argue that a portion of your realized capital gain should also be purified if the company had non-permissible income during your holding period.

Tesla's interest income has grown as the company's cash position has grown (roughly 25 billion in 2024). Against 97 billion in revenue, interest income is about 1.5%. Tesla passes the 5% screen easily.

If you sell Tesla at a gain and follow the strict purification view, you'd donate roughly 1.5% of your realized gain to charity for each year you held it. Most scholars don't require this for growth stocks, but the strict interpretation exists.

Reliance Industries: non-core revenue matters

Reliance (RELIANCE.NS) has a more complex corporate structure. The core businesses are oil refining, petrochemicals, telecom (Jio), and retail (Reliance Retail). All are permissible. Reliance also has a small financial services arm that generates some non-permissible income.

The 5% screen typically passes for Reliance with room to spare, but the precise percentage fluctuates quarter to quarter as the financial services business grows. During quarters when the financial services arm is growing faster than the oil/retail core, the ratio can drift upward. Stricter screens have occasionally flagged Reliance for re-review.

How to actually purify

Purification in practice is simple:

1. Calculate your total dividend income from a given stock in a year.
2. Multiply by the purification ratio (non-permissible income percentage) reported by your screener.
3. Donate that amount to a permissible charity.
4. Don't take a tax deduction for it (scholars generally agree that taking a deduction defeats the purpose of purification because you're benefiting from the impermissible income's tax shelter).

Most scholars allow you to donate to any legitimate charity, not just Islamic ones. Feeding hungry people counts. Funding medical research counts. Giving to a food bank counts.

The annoying part is the record-keeping. You need to track purification amounts year over year so you know what you owe. FaithScreener maintains a purification ledger for each holding in your portfolio view, making this less painful.

The bigger picture

The 5% non-permissible income rule is the most ethically demanding screen in Shariah investing because it's the one that actually imposes ongoing obligations. The debt ratio is a yes/no gate. The liquidity ratio is a yes/no gate. The non-permissible income rule is a tax on permissible stocks that happen to have imperfect revenue mixes.

And it's the one people actually skip. A survey conducted a few years ago found that fewer than 15% of Muslim retail investors who own "halal" ETFs actually calculate and remit purification amounts on their dividends. The other 85% assume the fund is doing it for them, which is usually incorrect. Most ETFs pay gross dividends and leave purification as an investor responsibility.

If you're going to invest in Shariah-compliant equities, take purification seriously. The math is small. The obligation isn't.