Mexico’s 2027 Customs Changes: What Shoppers Should Know

Planning to shop US or UK stores and ship your purchases to Mexico in 2027? An upcoming amendment to Mexico’s Customs Law makes accurate purchase records and shipment information especially important.

Published on 23 October 2026, the decree is scheduled to take effect on 1 January 2027. It addresses customs valuation, enforcement, and procedures involving goods suspected of being undervalued. Additional implementing provisions are due by 31 December 2026, so some details still need clarification. 

Here’s what has been announced, what remains pending, and how to prepare when shopping internationally with MyUS.

Information reviewed 12 November 2026. This article reflects the announced amendment; implementation details may change as further provisions are published.

What Is Changing in Mexico’s Customs Law?

The amendment strengthens how Mexican customs authorities can investigate declared values and handle suspected undervaluation.

Customs valuation concerns the value assigned to imported goods under applicable customs rules. It helps determine the charges due when goods enter a country.

The changes include:

• Closer scrutiny of declared values: Authorities must initiate verification proceedings when the declared value is below the legally determined transaction value of identical or similar goods.
• Revised precautionary seizure provisions: The amendment removes the previous 50% undervaluation threshold from the relevant seizure provision. Its application depends on further rules identifying the goods and procedures covered.
• Procedures for presenting evidence: The amendment provides mechanisms for affected parties to submit documentation supporting the declared customs value. 

For shoppers, the practical takeaway is to keep clear evidence of what you purchased and paid. A retailer invoice, payment record, and documented discount can help explain a transaction if questions arise.

What Does This Mean for Personal Online Purchases?

The decree is a broader customs enforcement measure. It should not be read as a confirmed new tax rate on every personal online order.

It also does not establish that every package forwarded through MyUS will require a new customer-facing procedure. The effect on an individual shipment will depend on the goods, applicable import procedure, and implementing provisions.

The decree also contains measures involving hydrocarbons and petroleum products, which are separate from the everyday consumer purchases discussed here. 

For now, focus on preparing reliable purchase records rather than assuming your next order will face a specific new charge.

Can You Still Shop US and UK Stores From Mexico?

The announced amendment does not itself ban purchases from US or UK retailers.

MyUS provides shopping addresses for eligible purchases from these markets, with onward shipping to Mexico subject to product restrictions and available services. Before buying, confirm that the retailer accepts your payment method and MyUS address, and that the item can be shipped to your destination. 

Remember that the retailer’s location, the country from which a package ships, and the product’s manufacturing origin are different pieces of information. Keep them accurate and ask for clarification when a shipment requires origin documentation.

How to Prepare Your Shopping Records for 2027

You don’t need to wait for January to organize your purchase information. These habits can help you respond more clearly if MyUS, a carrier, or customs requests documentation.

1. Save the Merchant Invoice for Every Order

Keep the retailer’s invoice showing:

• The seller’s name.
• The order or invoice number.
• The purchase date.
• Product descriptions and quantities.
• Item prices, currency, and total.
• Discounts applied to the purchase.

Download the document while it is readily available in your retailer account. If an order is divided into several deliveries, keep a record of which items belong to each package.

A shipping label or delivery notification may not contain enough information to explain the purchase.

2. Keep Evidence of Genuine Discounts

Shopping a sale is different from deliberately understating a purchase price.

If you buy a product at a discount, retain the invoice showing the amount paid. Keep relevant promotion details or a retailer-issued adjustment if they help explain the transaction.

Illustrative example: A retailer advertises a bag at US$150, but your invoice shows a promotional price of US$90. Save the invoice and payment confirmation supporting that purchase. If questions arise, those records provide context; they do not guarantee a particular customs valuation outcome.

3. Provide Accurate Purchase Information

When asked for item values, provide the actual transaction information and supporting records. Follow any instructions concerning shipping, insurance, or other amounts needed for customs valuation.

Do not enter a lower figure simply to reduce import charges. If an amount appears incorrect, explain the discrepancy and provide evidence rather than guessing.

Also avoid assuming a gift has no value. Ask how to document an item when there is no ordinary retail receipt.

4. Use Clear Product Descriptions

Specific descriptions make purchases easier to identify.

For example, “cotton short-sleeve T-shirt” provides more information than “clothing.” A product’s brand, model, material, and intended use may also be relevant when requested.

Keep retailer product links or specifications for unfamiliar items. If the invoice uses only a product code, additional information may help explain what the code represents.

5. Retain Your Payment Record

Keep a payment confirmation alongside the invoice, particularly when a refund, discount, or adjustment changes the amount paid.

Use the secure submission method specified in any request. Provide the relevant transaction information without including unrelated financial activity.

Review Your MyUS Account Before Shipping

Once purchases arrive at MyUS, open the package details and check for outstanding requests.

If a merchant invoice is required, the affected package will show an upload option under Action Required. Follow the instructions displayed, submit the relevant document, and check for confirmation.

Submitting a document does not mean it has already been approved. Review subsequent account updates and respond if additional information is requested.

Sign in to MyUS to review your packages and complete any outstanding actions.

Budget for Shipping and Applicable Import Charges

A retailer’s checkout total may not represent the complete cost of getting a purchase to Mexico.

Allow for:

• Delivery from the retailer to MyUS.
• International shipping.
• Any optional services selected.
• Applicable duties, taxes, and clearance charges.

Use the MyUS shipping calculator to explore shipping estimates. Review the options and charges available for your actual shipment before submitting a request.

MyUS’s Mexico guidance notes that duties, taxes, and customs fees may apply. For eligible shipments, prepayment options may be available; otherwise, the carrier may collect applicable charges. 

Do not assume that package consolidation eliminates import charges. Evaluate the combined shipment’s contents, value, and shipping requirements before deciding how to send your purchases.

What Still Needs Clarification?

The decree requires further provisions concerning the goods and procedures covered by the revised precautionary seizure rules. Those provisions are due by 31 December 2026

Until they are published and assessed, avoid assuming that:

• Every personal shipment will follow the same new process.
• A discounted product will automatically be detained.
• The decree creates a universal new online-shopping tax.
• Buying before January guarantees that older rules will apply.

The purchase date alone should not be treated as a guarantee of the customs treatment a shipment will receive.

Prepare for Your Next International Purchase With MyUS

The most useful step you can take now is to keep your shopping records complete and accessible. Save invoices, document discounts, provide accurate information, and check for requests before shipping.

As Mexico publishes further implementation details, review official updates and the guidance relevant to your shipment.

Already a member? Sign in to MyUS to check your packages and purchase documentation.

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We always aim to bring our members the best shopping options available, but some of the products featured in this post may have purchase restrictions. Please visit the merchant's terms of sale, shipping guidelines, and terms and conditions to find more information.