Brunei gives American passport holders one of the easiest entries in Asia, a 90-day waiver with no application. It also has customs rules that catch more visitors than any other country in the region, because they are unlike anything a traveler from the United States has encountered.
None of this is obscure. The Royal Customs and Excise Department publishes it plainly. Almost nobody reads it before flying.
There is no tobacco allowance. None.
Start here, because this is the one that costs people money at the counter.
The department states that cigarettes and tobacco “were deleted to be included in Passenger’s Concession (Personal Effect)”, and then leaves no room for interpretation:
Every cigarette / tobacco enter this country must be declared and duty must be paid at B$0.50 per stick.
Fifty Brunei cents per cigarette. Not per pack. A single carton of 200 cigarettes is B$100 in duty, and it is not optional or negotiable — the obligation is to declare, and the duty follows.
If you smoke, the practical answer is to arrive without tobacco.
Alcohol is permitted, but only for some passengers
Brunei is a Muslim country and does not sell alcohol. It does allow visitors to bring a limited quantity in, and the eligibility rule is explicit in the source:
For passengers who are not Muslims aged 17 and above who enter this country are allowed to bring in not more than a concession given as follows
The published quantity is two bottles of liquor of about two liters total, one liter per bottle, and twelve 330ml cans of beer.
That is a real allowance, not a token one. But it comes with three conditions that have no equivalent in most countries, and they are the part people miss.
The three conditions on alcohol
You must declare it. The department requires owners to declare imported drinks to the customs officer on duty at the point of entry. A special liquor form is available at every customs post and on passenger ships. This is a positive obligation, not a green-channel judgement call.
You must wait 48 hours between importations. The rule is that an importer “may only import alcoholic liquor not less than 48 hours since the last importation.” If you cross from Malaysia twice in a weekend, the second crossing is not another allowance.
It is for you, and for where you are staying. The source is unusually specific:
The alcoholic liquor shall be for the importer’s personal use and not to be given, transferred or sold to others. The alcoholic liquor shall be stored and consumed at the place of residence of the importer.
So the allowance does not make alcohol portable within Brunei. Buying a bottle for a Bruneian friend is outside the rule as written, and so is drinking it somewhere other than where you are staying.
Everything else
The general passenger concession covers personal items of your own for passengers aged 17 and above, with the published detail that the goods are personally used rather than new. Named limits include 60 milliliters of perfume and 250 millilitres of aromatic water.
No general value cap or undeclared-goods penalty listed
The concessions page sets out these categories and not much else. It does not publish a general value threshold for other goods, and it does not describe the penalty for failing to declare. We are not going to estimate either.
If you are arriving with something valuable, or with more than the quantities above, the useful move is to declare it and ask. Brunei’s rules are strict but they are also clearly published, which makes them easy to comply with and awkward to argue with afterwards.