ISAI Acquisition Tax by Municipality in the Riviera Maya: The 2 vs 3 Percent Myth Explained

ISAI (Impuesto Sobre Adquisición de Inmuebles) is Mexico's one-time property acquisition tax paid by the buyer at closing. It is not a single national rate. Each municipality in Quintana Roo sets its own rate, which is why the common shorthand of '2 to 3 percent' is misleading. In markets like Tulum, total closing costs including ISAI run higher than in other Riviera Maya municipalities, and buyers who budget on a flat figure often face a shortfall at the notario's table.

What exactly is ISAI and who pays it?

ISAI, the Impuesto Sobre Adquisición de Inmuebles, is a one-time municipal acquisition tax that the buyer pays at closing. It is not an annual obligation. You pay it once, when the deed transfers, and it becomes part of your documented cost basis for any future capital-gains calculation.

The tax is separate from the notario's professional fees, the fideicomiso trust setup fee, and any other closing-line items. It is also entirely distinct from ISR, which is the seller's income tax on any gain. As a buyer, ISAI is your line item; ISR belongs to the person selling to you.

Because ISAI is a municipal tax, not a federal one, the legal authority to set the rate sits with each of Quintana Roo's 11 municipalities under the Ley de Hacienda de los Municipios del Estado de Quintana Roo. That single structural fact is what makes the '2 to 3 percent' shorthand unreliable.

Why is the '2 versus 3 percent' figure a myth?

The 2-to-3-percent range circulates in marketing articles because it is directionally true at the low end of the scale, but it flattens a more complicated reality. Each Quintana Roo municipality, including Benito Juárez (Cancun), Solidaridad (Playa del Carmen), Tulum, and Puerto Morelos, sets its own ISAI rate independently. The rate that applies to your purchase is determined by the municipality where the property is registered, not by the region as a whole.

The myth does real financial damage in two ways. First, buyers who budget on the lower figure can be underprepared at closing. Second, and more consequentially, the declared purchase price on the deed is the base from which ISAI is calculated, so any temptation to under-declare the price to reduce the tax creates a lower cost basis that inflates your taxable gain when you eventually sell. A reputable notario will refuse to participate in under-declaration, and the practice is illegal under Mexican law.

The honest answer is that your notario will calculate ISAI on the actual declared value of your specific property in its specific municipality. That is the only figure that matters.

How does ISAI vary across Riviera Maya municipalities?

Verified municipal rate schedules change with each fiscal year and are set locally, so the precise percentage for any given municipality in 2026 must be confirmed with your closing notario or transaction attorney. What the available data does confirm is that Tulum stands out as the highest-cost closing environment in the region.

Closing costs in Tulum, after accounting for the 2025 ISAI acquisition tax adjustment, run in the range of roughly 8 to 10 percent of the purchase price. That is a materially higher band than buyers typically encounter in Playa del Carmen, Puerto Morelos, or Cancun, where total closing costs tend to land lower. Puerto Aventuras and Akumal fall within the Solidaridad and Tulum municipal boundaries respectively, so buyers in those communities should confirm which municipality governs their specific parcel.

The practical implication is straightforward: do not carry a single closing-cost percentage from one listing to another. Ask your transaction team to produce a municipality-specific closing-cost estimate before you make an offer.

How is ISAI calculated at the notario's table?

The notario público is the legally appointed public official who closes every Mexican real estate transaction. Calculating and collecting ISAI is part of the notario's statutory function, not an optional service. The notario applies the applicable municipal rate to the declared transaction value on the deed and collects the tax at closing.

The declared value matters enormously for two reasons. First, it is the base for ISAI itself. Second, it becomes your documented acquisition cost for future capital-gains purposes. A higher declared price means a higher ISAI bill today and a lower taxable gain when you sell. A lower declared price saves a small amount today and costs you significantly more in ISR later, in addition to being illegal.

Your closing attorney or the notario's office will produce a line-item closing statement before the deed signs. Review every line, confirm which municipality the property sits in, and verify that the ISAI figure reflects the current municipal rate applied to the full declared purchase price.

Does ISAI affect my US or Canadian tax filing?

ISAI is a buyer-side closing cost, and it is deductible from your taxable gain when you eventually sell, because it forms part of your documented cost basis. US buyers should record ISAI on their closing statement precisely and provide it to their cross-border CPA alongside the notario fees, fideicomiso trust setup fees, and the full purchase price. These figures together establish the cost basis that reduces your US capital-gains exposure on a future sale.

FIRPTA, the US withholding rule that often comes up in conversations about Mexico real estate, has no application here. FIRPTA governs US buyers purchasing from foreign sellers of US property. It has no reach over a transaction in Mexico. The confusion arises because the acronym sounds relevant; it is not.

Canadian buyers face their own cross-border reporting obligations under CRA rules for foreign property. ISAI and other closing costs are similarly relevant to establishing the adjusted cost base. A Canadian accountant with foreign-property experience should review the closing statement before the tax year closes.

What should I budget for total closing costs in the Riviera Maya?

ISAI is one component of a broader closing-cost stack. The full stack typically includes the notario's professional fee, the fideicomiso (bank trust) setup fee for foreign buyers in coastal zones, government registration fees, and any legal or representation fees your transaction attorney charges. Together these items add up to a closing cost that varies meaningfully by municipality and by purchase price.

Tulum, as noted, runs at the higher end of the regional range. Other municipalities tend to come in lower, though the exact figures depend on the declared purchase price and the current municipal schedule. The consistent guidance from transaction professionals is to budget conservatively and request a written closing-cost estimate specific to the property address before signing a purchase agreement.

One practical note for buyers coming off US tax season: closing costs including ISAI are not deductible on your US return in the year of purchase the way mortgage interest might be on a primary residence. They are capitalized into your cost basis and reduce your gain at the time of sale. A cross-border CPA can walk you through the timing and treatment.

How do I confirm the correct ISAI rate for a specific property?

The most reliable source for the current ISAI rate on a specific property is the notario who will close your transaction. Notarios in Quintana Roo work with the current municipal Ley de Hacienda and can produce a closing-cost estimate that reflects the actual rate for the municipality where the property is registered.

Your transaction attorney or the MWH team can identify which municipality governs a given address, since municipal boundaries in the Riviera Maya do not always follow the names buyers associate with a location. A property marketed as being in Akumal, for example, may fall under the Tulum municipality, which carries its own rate structure.

If you are comparing two properties in different municipalities, request a closing-cost estimate for each. The difference in ISAI alone can affect your total acquisition cost by a meaningful amount on a luxury purchase, and it is a number worth knowing before you negotiate a price.

Is sargassum relevant to where I buy, and does it affect property value?

Sargassum is a real and recurring condition on parts of the Riviera Maya coast, with higher accumulation typically running from roughly March through October. Its relevance to a property purchase depends entirely on location. Beaches in Cancun and Puerto Morelos have historically received more consistent municipal and hotel-corridor cleaning effort. Tulum's more exposed and less developed coastline tends to see heavier accumulation with less systematic removal.

Playa del Carmen, Puerto Aventuras, and Akumal sit in the middle of that spectrum, with variability by specific beach and season. Buyers purchasing beachfront or beach-access property should ask directly about sargassum history for that specific stretch of coast, not the municipality in general.

Sargassum does not uniformly suppress property values, but it does affect rental income on beachfront units during heavy-accumulation periods. If vacation-rental yield is part of your investment thesis, factor in seasonal beach conditions alongside the ISAI and closing-cost picture when you compare properties across municipalities.

Where can I get a property-specific closing cost estimate?

Our team works with transaction attorneys and notarios across the Riviera Maya and can connect you with a municipality-specific closing-cost breakdown for any property you are evaluating. The estimate will include ISAI at the current applicable rate, notario fees, fideicomiso setup, and registration costs, so you have a complete picture before you make an offer.

If you are currently reviewing listings or comparing markets across Tulum, Playa del Carmen, Puerto Morelos, Cancun, Puerto Aventuras, or Akumal, we are glad to walk through the closing-cost differences by location alongside the property itself. Reach out to our team or explore current listings to start that conversation.