Tax reform for Mercado Livre and Shopee sellers: what changes in 2026, 2027, and through 2033

For Mercado Livre and Shopee sellers, 2026 is a test year: CBS is 0.9% and IBS is 0.1%, but businesses that meet their reporting requirements are exempt from paying, and the test rates don’t apply to Simples Nacional. The real change begins in 2027, when CBS replaces PIS and Cofins, and continues through 2033, when ICMS and ISS are eliminated. Along the way, two changes will directly affect marketplace sellers: split payment and platform responsibility for the seller’s Nota Fiscal.

This article summarizes what the law and official communications say as of October 2026. It isn’t individual tax advice; work with your accountant to choose your tax regime and options.

#The tax reform timeline

The timeline is set out in Constitutional Amendment 132. IBS increases as ICMS and ISS decrease; the reference rates for each year have yet to be defined, so be wary of anyone already quoting exact rates for 2029 and beyond.

#2026: what you need to do

If you’re under Simples Nacional or are a MEI: the 2026 test rates don’t apply to your transactions. You’ll continue paying tax through DAS, as before.

If you’re under the regular tax regime (Lucro Presumido or Lucro Real):

• Since August 3, 2026, electronic invoices without the IBS and CBS fields have been rejected. The fields must show 0.1% IBS and 0.9% CBS.
• Businesses that meet their ancillary tax obligations are exempt from paying IBS and CBS in 2026, but continue paying PIS and Cofins as usual.
• Any amounts paid are offset against PIS and Cofins for the same period.

If you issue invoices through Mercado Livre’s invoicing system or an ERP, make sure it already fills in these fields. I cover the invoicing system in invoicing on Mercado Livre.

#Simples Nacional: the option available in 2027

Simples is here to stay. Businesses under Simples or MEI continue to follow the rules for those tax regimes. The new development is an option:

• Starting in 2027, businesses under Simples can pay IBS and CBS outside the DAS, under the regular tax regime. In that case, these amounts will no longer be charged through the DAS.
• The option is semiannual and irrevocable for each six-month period. You can choose in September (for the first half of the following year) or March (for the second half).
• For the first half of 2027, the selection window ran from September 1 to 30, 2026. The next window is in March 2027.

Why choose this option? Because business customers buying from a Simples business can only claim IBS and CBS credits for the amount actually charged under Simples, which is lower. Businesses that sell to other businesses may become more competitive by paying these taxes separately. For sellers who sell to end consumers on marketplaces, who cannot claim credits, the impact is usually small. Talk to your accountant before making a choice.

Two changes to Simples in 2027 are already law: you’ll choose the tax regime in September of the previous year, and the 12-month period used to calculate the effective tax rate will shift back by one month.

#Marketplace: the platform becomes responsible for the tax

The complementary law for the tax reform defines a digital platform as one that facilitates remote sales and controls at least one of these: billing, payment, terms and conditions, or delivery. Mercado Livre and Shopee meet this definition.

The platform is jointly liable for the seller’s IBS and CBS if the seller is based in Brazil and:

• does not provide transaction information to the tax authorities; or
• is a taxpayer and does not issue an invoice for the transaction amount.

The platform is not liable if it provides the information and, once split payment is in place, passes along the data needed to separate the tax. With the seller’s consent, the platform can issue tax documents on the seller’s behalf and pay IBS and CBS.

The practical impact is clear: marketplaces will enforce invoice requirements more strictly, because they will share the risk. Sellers who still sell without invoices should prepare.

#Split payment: tax withheld at payment

With split payment, the payment processor separates the IBS and CBS amounts and sends them directly to the tax authorities when the payment is settled. For sellers, this means the money that reaches their account is already net of tax.

Integration testing with payment providers began on October 15, 2026, in a controlled environment, with no impact on real transactions. As of October 2026, the Federal Revenue Service had not announced when split payment would go live or become mandatory.

In practice. An electronics seller under the Presumed Profit tax regime found out about the August change when invoices were rejected: the ERP they used wasn’t filling in the IBS and CBS fields, and their FULL shipments were held up for two days, leaving orders stuck at the distribution center. A system update fixed the issue, but the delay caused late shipments that week. The 2026 tax was only a test; the operational problem was real.

#What to do now

1. Confirm your tax regime and whether the 2026 testing rules apply to you.
2. Make sure your invoices include the new fields if you’re under the regular tax regime.
3. Issue an invoice for every sale. With platforms sharing responsibility, selling without an invoice will become harder.
4. Talk to your accountant about choosing the Simples option in September or March if you sell to businesses.
5. Track your margin on every sale using your actual tax rate. Once the transition rates are set, your prices will need to reflect them.

#How tax affects the margin on every sale

The tax reform will gradually change tax rates year by year through 2033. If you price based on a tax rate you’re just guessing at, you’ll make more and more mistakes. Milewa applies your tax regime’s rate to every sale on Mercado Livre and Shopee, then shows your margin after tax. When the rate changes, just update it in your CNPJ settings so your margin and ideal price stay accurate. Learn how tax affects your margin today in the tax that goes up on its own.