If I don't declare a not-yet-used engagement ring at airport security, am I smuggling jewelry?

If I buy a ring in the US, put it in my bag and do not declare the ring I am smuggling jewelry? How is that different from buying the ring, wearing it round my neck on a chain (or on my own finger for that matter) and not declaring it? Am I supposed to declare my own jewelry that I already paid for (including taxes upon purchase)?

First off it’s not airport security you should be concerned about. It’s customs at the destination country.

Whether you need to declare it to customs depends very much on where you are going, where you live and what you intend to do with the ring.

As a visitor most countries will let you take in reasonable personal belongings on a temporary basis. If it’s extremly valuable they may require temporary import paperwork and a deposit but most of the time that is more trouble than it is worth.

You can normally bring back stuff that you bought at home and took abroad.

On the other hand if you are returning home with a ring you bought aboroad then unless it was very cheap you most likely need to declare it. Your country is unlikely to care that you already paid foreign tax on it.

And if you are taking a valuable item to a foreign country and don’t intend to bring it back out then again you likely need to declare it.

If you are immigrating (changing your country of residence) there are often special rules that let you bring in more than the normal allowances without paying duty/tax but taking advantage of these rules may require specific paperwork.

Customs officers don’t know for sure why someone is bringing an item into the country so they have to make educated guesses. Whether an item is in it’s original box is one of the things they are likely to consider. In general when it comes to customs duty the burden of proof is on the traveller.

I checked this out for Canada, and the rules seem to be deliberately vague.

As a visitor, you can bring certain goods into Canada for your own use as “personal baggage”. Personal baggage includes clothing, camping and sports equipment, cameras and personal computers. […] You must declare all goods when you arrive at the first CBSA port of entry. […] The border services officer may ask you to leave a security deposit for your goods, which will be refunded to you when you export the goods from Canada.

There is no mention of a value of personal belongings below which declaration is unnecessary. On the other hand, the Canada Landing Card does not ask for the value of your personal belongings, and there certainly isn’t a long lineup of visitors to Canada volunteering that information at Immigration.

All of that assumes that the goods will not be left in Canada. It’s phrased like that, so it doesn’t matter that technically someone else is taking the ring out of Canada from the person who brought it in.

I would estimate that, in Canada, the authorities would have to demonstrate that you intended to leave the ring in Canada to successfully prosecute you for smuggling. If you wanted to be safe, or your ring was very expensive, you could declare it on entry. As long as you take it out of the country you won’t pay duty.

You’re generally not supposed to declare the stuff you already paid for and imported legally but you might be required to prove you did not buy them abroad, otherwise the regular import rules apply.

The details will depend on the specific country and a few other things (e.g. whether you are a resident, currently moving to the country, etc.) but you are typically allowed to import things worth between USD 500 to 1000, for your personal use, if you carry them with you. In all the counties I know a little about, this allowance cannot be shared between several people to import a more expensive item.

Anything over that value is typically going to be dutiable (there are very complex rules on how much duty you have to pay on what type of goods) and taxable (including VAT in countries that have it).

Now, the question becomes: What about the stuff you take with you on your trips? Between the Apple laptop from last year, the new iPhone, the designer clothes and your Swiss watch, you’re already over USD 500. In practice, if it’s all regular used tourist gear, customs officers do not bother. From the perspective of the country you are visiting, you will take everything back with you soon and aren’t importing anything for good. From the perspective of the country you come from, it has probably all been properly imported and taxed before.

Being too picky about those things would mean expending considerable resources for a limited return and would put an unreasonable burden on either citizens or the tourists that come to spend money in the country so it seems reasonable to tolerate it. Because of this, if you throw your old watch or go to Switzerland without one, buy a new watch there, mail the receipt and come back with the watch on your wrist, you might just get away with it. But you are still supposed to comply with customs rules both in the countries you are visiting and the country you reside in and the burden of proof might really be on you.

If you want to do everything by the book and avoid paying duties on goods in transit or used during a short visit, you should secure some evidence that the goods have been properly imported (to be able to reenter the country you initially left), provide some guarantee that you will reexport them soon (to be able to enter the country you are visiting without paying the full importation costs) or follow some temporary exportation/importation procedures. For expensive equipment or perhaps a car, customs might just bother and I know people who had such paperwork for their gear. Among other things, that’s what the ATA carnet and the carnet de passages en douane are for.

As a random example, here is what the rules in Canada look like:

1. Canadian residents may temporarily export personal effects for use on trips abroad.

2. On returning to Canada, it is the individual’ s responsibility to establish that such items were initially taken out of Canada and were not acquired abroad.

So formally it’s really up to you to prove you imported the ring properly, even if you bought it a long time ago and wear it all the time. And jewellery appears to be especially sensitive:

10. Most jewellery items, with the exception of watches having serial numbers and original pieces of jewellery that are numbered by the manufacturer, are not uniquely identifiable. Since the Y38-1 label is unsuitable for use with items such as jewellery, individuals taking valuable pieces of jewellery or other similarly non-identifiable articles abroad should be aware that the CBSA will not document such goods on Form Y38. If an individual wishes to take steps to avoid unnecessary delays and facilitate reimportation of these articles, an appraisal report should be obtained from a qualified gemmologist, jeweller, or insurance appraiser, together with a signed and dated photograph of the jewellery. This should be accompanied by written certification that the jewellery in the photograph is the same jewellery identified in the appraisal reports. Individuals should be aware that this appraisal documentation may be expensive to obtain.

11. Jewellery is a sensitive commodity given special attention during CBSA clearance. Individuals who are unable or unwilling to obtain documentation should consider leaving such jewellery in Canada to avoid problems when they return.

Failing that, you could be asked to pay duties or even a penalty upon coming back to the country. The customs do not even have to prove you bought the ring abroad, you have to prove you did buy or import it in Canada earlier.

You are only allowed to bring into a country x amount of good(s) (this varies per country). For example:

The UK law for arrivals from non EU countries states:

You can bring in other goods worth up to £390 without having to pay
tax and/or duty.

Bringing in items worth more than this amount is liable to tax, again e.g.:

…(if) you go over your allowance you’ll have to pay any Customs
Duty, Excise Duty and/or Import VAT due (VAT will also be due on any
duties that may be charged).

If you fail to declare any item over the threshold (i.e. you go through the green lane not the red lane). You will not have paid the relevant tax on said item and are therefore breaking the law.

Definition of smuggling is:

Smuggling is the illegal transportation of objects …. across an
international border, in violation of applicable laws or other
regulations.

So in the circumstances above, yes you are smuggling.

This is regardless of where on your person the item is. If you’re wearing it you’re still planning on bringing an amount of goods into the country. How does customs know that you don’t plan to take off that expensive watch and sell it later?

You can (as stated in the related question Item held by customs until I pay tax; what are my options?) claim the tax back when you leave the country in question, providing you still have the item. This is what you should do by law.