Rules change, but here’s the latest

Do I need a U.S. passport to leave the country?

In general, yes. Exceptions include land or sea travel to Canada, Mexico, the Caribbean and Bermuda, where a photo ID plus proof of citizenship, such as a birth certificate, may be enough for now. Practices may vary from official policies. People driving into Mexico, for instance, are often waved through checkpoints with only a driver’s license or a photo ID.

What else do I need?

Depending on the country you visit, you may also need a visa. Contact the country’s government for details.

How do I get a passport?

The best information source is www.travel.state. gov. Click on “Passports for U.S. Citizens” and follow the instructions. Under fee increases announced last week, a new passport costs $100 for adults and $85 for children younger than 16; renewals run $75 .

When should I apply for a passport?

As far ahead as possible. It takes the State Department about four to six weeks to process your application, officials say. But last year, some applicants waited for months because of a backlog. Don’t take a chance, and don’t forget to add in extra time if you need a visa.

My passport expires in four months. Can I travel on it?

That depends on the country you’re going to. Some governments require that you have at least six months left on your passport.

I have one blank page in my passport. Is that OK?

That also depends on the country. Some require two to four blank pages for visa stamps, the State Department says, and some airlines won’t let you board without them. Adding pages is free. To find out how, go to www.travel .state.gov and click on “Frequently Requested Information” under “Passports for U.S. Citizens.”

Did border rules recently change?

Yes. On Thursday, the U.S. government was to have ended what it called “the routine practice of accepting oral declarations alone at land and sea ports of entry” from U.S. citizens. So now American adults are expected to present at least a birth certificate or other proof of citizenship, plus a government-issued photo ID, such as a driver’s license, to cross borders by land or sea. Children 18 and younger need only a birth certificate. Americans who fly still need a passport, which is also accepted for land and sea crossings.

What other changes are ahead?

By June 2009, Americans may need a passport or a special high-security document to return from Canada or Mexico by land. One document for this purpose will be a passport card, about half the cost of a passport, that the U.S. government expects to start issuing this spring. For updates, go to www.travel .state.gov or the website of the U.S. Department of Homeland Security, www.dhs.gov.

Why is crossing borders so complicated?

Each country sets its own entry requirements. Also, the ongoing U.S. effort to require more travelers to carry passports within the Western Hemisphere has drawn protests from some business interests and governments, which worry it may discourage travel. Gearing up for the change has proved complicated, with high demand last year causing backups in passport processing. So the federal government keeps making exceptions to the proposed rules and shifting enforcement deadlines. Confused? The simplest solution is to get a passport now. It’s good for all border crossings.

What is on a passport’s computer chip?

The State Department says it contains a digitized version of your ID photo, plus data from the passport’s main page: your name, gender, date and place of birth, and the passport’s number, issue and expiration dates. When a border officer waves the passport near a mechanical reader, the machine activates the chip’s tiny antennae, causing it to broadcast its data.

Is the chip a security risk?

The government and many private security experts say it isn’t because the chip can be read from only 4 inches away, and it can’t be read at all when the passport booklet is shut. But other experts say that the chip could be copied and that it may be possible for others to track you or steal data if the booklet falls open.

What goods can I bring back into the U.S.?

The answer is complicated because there are hundreds of regulations. For guidance, go to www.cbp.gov, U.S. Customs and Border Protection. Click on “Travel Alerts” under “Quicklinks,” then choose “Prohibited and Restricted Items.” Food and plants probably cause travelers the most trouble. Study the rules to avoid buying a $200 delicacy you’re forced to surrender.

How much can I bring back without paying duty?

Most often the limit is $800 worth of goods, but the amount varies by destination, and there are many exceptions. For details, go to www.cbp.gov, click on the “Travel” tab and choose “Know Before You Go.” Be prepared to plow through a 60-plus-page brochure.