What actually changes
Four things have real deadlines or real money attached, and one of them catches almost everyone.
| Social Security number | On an immigrant visa, tick the Social Security box on your DS-260 and the card is mailed to your U.S. address about 7 to 10 business days after you land. No office visit. On a work visa (H-1B, L-1) you apply in person at a Social Security office after you arrive. |
| Social Security taxes | There is no social security agreement in force between the U.S. and Mexico. U.S. Social Security and Medicare come out of your U.S. pay from the first paycheck, and there is no certificate of coverage to exempt you. |
| Household goods at the border | Furniture and household effects enter duty free only if you owned and used them in your household for at least a year. Anything shipped separately from you needs CBP Form 3299 and a full inventory. |
| Cash at the border | There is no limit on how much money you may bring into the U.S., but more than $10,000 in cash or equivalents, per family travelling together, has to be declared. Not declaring it is how it gets seized. |
| Bringing a dog | Mexico is not on the CDC's high-risk list for dog rabies, so the paperwork is short: the free CDC Dog Import Form filed 2 to 10 days before travel, a microchip, and a dog that is at least six months old and healthy on arrival. Your airline will have its own rules on top. |
| Driving and credit | There is no national U.S. licence. Each state sets its own deadline once you become a resident, and a Mexican licence with an International Driving Permit only covers you briefly. Your state's clock is in the app. Your Mexican credit history does not travel. Expect to start from zero: a secured card, or a card from a bank that underwrites new arrivals. |
Rules here change often. Confirm current requirements at the official source before you act. (reviewed Aug 2026)
Your Mexico to USA timeline
- 2 to 3 months outCollect the documents that are slow to replace from a distance: birth and marriage records, school transcripts, vaccination records, and anything that needs an apostille.
- 6 to 8 weeksBook the move and build the inventory. The one-year ownership rule is what makes household goods duty free, and the inventory is what proves it.
- 4 weeksSort banking on both sides, and plan how money crosses. Keeping a Mexican account is fine, but it can trigger U.S. reporting once you hold more than $10,000 abroad.
- Crossing weekDeclare goods and any cash over $10,000 at the port of entry, with CBP Form 3299 for whatever arrives separately. Then the Social Security card, a U.S. phone number and a bank account.
- First 30 daysHealth insurance enrolment, driver's licence, schools if children are coming, and the state deadlines that started the day you arrived.
Kids, pets, which visa, which U.S. state, your actual move date: answer a few questions and every task above lands in a week-by-week plan you can check off and share. Free.
Common questions
Do I pay social security in both countries?
No agreement is in force between the U.S. and Mexico, so U.S. Social Security and Medicare start with your first U.S. paycheck and there is no exemption to claim.
Can I bring my furniture duty free?
Generally yes, if you owned and used it in your household for at least a year. Goods that travel separately from you need CBP Form 3299 and a full inventory.
How much cash can I bring across?
Any amount, but more than $10,000 per family travelling together must be declared at the border. The rule is about declaring, not about permission.
What does it cost to move from Mexico to the U.S.?
It depends on distance from the border, volume, and whether you cross by road or ship. Quotes for the same load vary widely, so get three of them six or more weeks out.