Why interest is a taxed act
The IVA Law taxes anyone who, within national territory, supplies independent services (art. 1, sec. II), and defines "service" with an extremely wide net that ends with "any other obligation to give, to do or to refrain from doing" (art. 14, sec. VI). Financing —giving money today against repayment with interest tomorrow— falls squarely within it. The taxable base is the interest (the principal is not consideration), and even incidental acts have a payment mechanism provided for (art. 33). Honest starting point: interest = taxed act, except where expressly exempt.
The map of exemptions (art. 15-X)
- Financing of exempt or 0%-rated transactions (15-X-a): if you sell on credit something that carries no IVA, the interest on that financing carries none either.
- Financial system (15-X-b): interest received or paid by banks, credit unions, factoring firms and SOFOMES that qualify as part of the financial system for the LISR (Income Tax Law) — but with a huge carve-out: it does not apply to loans granted to individuals who carry out no business or professional activity (that is why your card and your personal loan DO carry IVA on the interest, and your business loan does not).
- Housing mortgages (15-X-d): exempt, no matter who lends.
- Workers' savings funds, certain securities and financial transactions — specific cases from the same catalogue.
The individuals' myth, put in its place
"Between individuals it triggers no IVA" is repeated so often it sounds like law. It is not: there is no blanket exemption for a loan between individuals — the transaction fits the taxable event and is not in art. 15-X. What does exist is a practical reality: the isolated lender does not invoice, does not pass on the tax, and the SAT (tax authority) has historically pursued that act very little. It is a position held up by inertia, not by law — and hard to defend on paper. The habitual lender (an individual with activity, or a non-financial legal entity) doesn't even have that alibi: it must pass on IVA over its taxed interest, issue a CFDI (digital tax invoice) and report it.
Quick mental table
- Housing mortgage: exempt — whoever the creditor is.
- Bank/SOFOM (financial system) lends to a company or a person with activity: exempt (15-X-b).
- Bank lends to a consumer (card, personal, auto): interest with IVA. That's why the "IVA-free" CAT differs from your statement.
- Non-financial company or habitual lender lends: interest taxed at 16%, CFDI and pass-through.
- Isolated loan between individuals: technically taxed; in practice almost never passed on — a risk each person decides to run, informed.
Impact on how a loan is structured
IVA changes the real cost: 16% on the interest is more than two extra points on a 15% rate. When comparing offers, always ask "does your interest carry IVA?" and run the numbers with total cost and CAT. And when structuring as a creditor: the housing-mortgage exemption and the financial-system qualification (via a SOFOM) are, among other things, final-price decisions for your borrower — part of the analysis of when the SOFOM suit is worth it.