Do I need to have money when entering a country as a tourist?

I dont think they ask you to show money when you enter a country. They will probably ask where would you be staying and how long your stay would be like. They are in general make a judgement call and if you pass it, you are in. Simple as that. Answer the questions, dont overexpose and simply be nice.

I do a fair amount of travel for work, and I’ve never had a customs or border agent ask me how much local currency I had on my person at the time of my arrival. They have also never asked me to produce bank statements (though the terms of my UK visa said I should be prepared to show them if asked).

That being said, if you are travelling from the airport via taxi or public transport, having some local currency (and small change) on hand is very helpful.

Caveats: I’m female, with an American passport.

Several related requirements do exist:

• In the Schengen area or in the UK for example, you need to have sufficient means to cover the costs of your stay. You don’t have to carry cash but you should in principle be able to show through a bank statement or any other type of evidence that you have a certain amount of money at your disposal. Formally, how much money you need does not depend on how frugal you intend to be but is defined by the country in question. In practice, if you don’t need a visa for short tourism visits, you probably will not be asked about it or the border guards will be satisfied with being shown a credit card but the requirement does exist. On the other hand, people who need to apply for a visa in advance frequently have to provide relevant documentation.
• Some countries, most famously perhaps the German Democratic Republic, made it mandatory for foreign visitors to exchange some “hard” currency (Deutsche Mark in that case) in the local currency at a disadvantageous (to say the least) rate. Today many countries have some form of currency controls (regulated exchange rate, maximum amount of money exchanged per day, import and export ban, mandatory use of the local currency, etc.) but I am not aware of any that would require you to bring in foreign currency (quite the opposite: you need cash to get local currency on the black market but the authorities typically much prefer you to change money through official channels).
• Some countries have some form of tourist tax. Often, it’s a small amount collected by municipalities or local authorities through hotel bills (France, Italy, Spain, Germany…) or some similar scheme but Bhutan has a daily visitor fee of 250 USD which might be closer to what you are asking about. In that case, you do not merely need to show you have the money or convert it to cash that you can only spend in the country, you have to part with it as well! (But you also get something for it, it’s more like a compulsory tour purchase.)
• Visa fees. In your scenario, you would have obtained a visa in advance so it’s probably a little out of the scope of your question but some countries are much less restrictive than the US or European countries and happily give tourists visas on arrival with minimal requirements. However, unlike a visa exemption rule, you still need to pay visa fees and therefore to have some money or means of payment. Also, bribes are not unheard of in some parts of the world and they presumably require cash.

Finally, as far as I know, border guards typically can refuse entry for whatever reason they feel like. In some countries, there might be some guidance or a limited list of legal reasons to refuse entry but some are sufficiently vague to fit just about any situation and you have basically no recourse, even if you have a visa. So, strictly speaking, they can certainly ask how much cash you carry and decide they don’t like your answer. Also, if you are denied entry, usually you won’t simply be “asked” to return to your home country, you will be forced to.

Personally, traveling on a passport allowing visa-free stay in many countries, I have never been asked to prove I have enough money but I have been asked if I was not carrying more than X000 dollars/euros in cash (in many countries there is a limit above which declaration is mandatory).

Customs officers generally make a judgement call. They want to know that you will be in the country only temporarily, and that you will not try to work without a work permit. I often arrive in countries with no local cash at all, but I have a bank card where I can withdraw cash on arrival and that’s no problem. If you have no cash, no credit card, and no bank card, how will you eat? Where will you sleep? They begin to suspect there is something you are not telling them.

On the other hand if you arrive with $10,000 in cash, that will draw attention for other reasons. They want everything you bring to make sense and match with everything you say. You’re not planning to work? Then why have you brought your special tools that you use for being a welder or a hairdresser or a fashion photographer? You’re just here to visit a friend? Then why have you brought all the clothes you own, family photo albums, and a collection of “we’ll miss you!” cards from friends and family? How much money you have with you fits into that thought process as well.

There is an aspect of unfairness to all this, because it’s not as simple as “bring $X and you’re all set.” It is a judgment call. Laws say things like “enough money to meet your needs” but obviously different people have different needs, and different lengths of trips, and different support from friends and family. Nothing is ever cut and dried at borders. And then there’s even just the matter of whether they check. If you’re well dressed and are carrying credit and debit cards along with stuff that suggests tourism, you’ll be treated differently than if you look like a hippy and are carrying only one debit card and some pot smoking paraphernalia. Once you’re in secondary they can check your criminal record, search the contents of computers, call the people you’re visiting and so much more that they would never do at primary. And then they might conclude they don’t want to let you in. I’ve watched many episodes of Border Security (I watch the Canadian one, but there are versions all over the world) and listening in on them discussing how much money someone has it’s clear there’s no obvious number you know you’re ok as long as you have. It’s an overall presentation: logically, does what you are saying make sense and hang together? If not, and they decide you’re arriving to work then they won’t let you in. If you’re wandering the world with no clear ties to some other place, they might decide you want to stay here without applying to do so, and then they won’t let you in. Etc. You want to make sure you get across to them the truth of your situation, and it had better make sense.

Technically no, depending on the country you’re visiting you’re probably not legally required to be in possession of a certain amount of spending money, especially in the day and age of plastic money.

Having said that customs officers have broad abilities to turn you away if they suspect you of not going to adhere to the terms of your visa. One of those triggers may be not having spending money despite being on a tourist visa, but I doubt it’s codified anywhere.

I’ve travelled to a fair number of countries with no spending money with no issues, including the U.S. last year, in each case with the plan to visit an ATM in the airport (successfully). I’ve never been asked how much money I was taking into the country, other than the standard arrival document asking whether I had over a certain amount. The caveat being that I’m an Australian and I’ve noticed customs officers often apply different standards to different nationalities.