Purification

The process of cleansing investment returns by donating the impermissible (haram) portion to charity. Even Shariah-screened stocks may generate small amounts of interest income or revenue from non-compliant activities. Investors calculate the percentage of impure income and donate that proportion of their returns to charity (without intending it as sadaqah or seeking spiritual reward for that portion).

Halal investment platforms and robo-advisors like Wahed Invest often automate purification calculations. AAOIFI and other bodies provide guidelines for calculating the purification ratio.

Purification (tathir) is the practice of donating the impure sliver of investment income that even Shariah-compliant portfolios generate. Halal equity screens tolerate small amounts of prohibited revenue — under AAOIFI's equity standard, up to 5% of a company's income may come from non-compliant sources (interest earned on corporate cash, incidental haram lines) — on the logic that total avoidance is impossible in modern markets. The tolerance comes with a duty attached: the investor must calculate their proportional share of that impure income and give it away, with no expectation of reward and no zakat credit — it is returning money that was never cleanly yours, not charity.

Mechanics: fund managers of halal funds (Amana, SP Funds, Wahed) typically publish per-share purification amounts annually or purify at the fund level; stock pickers rely on screening apps — Zoya and Musaffa both compute per-share purification figures from company financials — then donate the total to any general charitable cause (most scholars direct it to broad public benefit rather than mosque construction, given its origin). Dividend purification is the standard obligation; some boards also recommend purifying capital gains, a stricter minority practice. Our purification calculator implements the standard methodology.

The discipline matters beyond arithmetic: purification is the mechanism that makes the 5% screening tolerance ethically coherent rather than a loophole.