Unlike western countries, you can usually get a tourist visa, leave the country for a few hours and then return and get a new visa. This practice is known as a “visa run”. The difference in visas between the countries determines how often you need to pay for flights or suffer a few hours on a bus rather than how long you can spend in the country itself.
Sometimes, the visas issued on arrival are exemptions from needing a visa rather than an actual visa. These exemption cannot be extended like a visa can. Bali is especially tricky like this.
Accidentally overstaying a visa by a couple of days is not always a problem - they will likely just fine you a small amount in the airport or at the border when you try to leave. It will not make any difference to your chances of re-entering the country smoothly in the future. Overstaying by weeks is more serious and you should go to an immigration office well before flying to deal with the consequences. If you don't, there may be some nasty surprises on the day of your flight.
You are usually required to have a flight out of the country you are about to enter. If you do not have this arranged, buy a cheap one that can be cancelled later (expedia.com has a checkbox on their search tool that helps you find fully refundable flights and their cancellation process is very smooth). You can also have this process automated for you by using flyonward.com bestonwardticket.com or onwardflights.com. Some people simply engage in minor forgery and edit the PDF of a previous flight they took by changing the dates and printing it out.
I've used flyonward about three times with no major problems. If you use this, be aware that the ticket booking they do for you is a manual process. It only gets done during the day (Thailand time zone), so book plenty of spare time before your flight. Doing so requires selecting the more expensive 48 hour expiry so the price on their homepage is a bit misleading. In recent months complaints about flyonward not delivering the goods have become more frequent so people have been recommending bestonwardticket.com instead.
If the country you’re entering has land borders with other countries, you could try to have a story ready about the bus trip you are planning to the next country (which country, which border crossing and on what date). It's probably not worth the risk though - deportation sucks; been there, done that.
Country by country
Visas are changing constantly and they depend on the home country of the applicant. I've made a brief guide below and you should refer to Wikipedia and the embassy web sites for more reliability and depth. For example, if you’re from the USA and going to Thailand, go to the Thai embassy in Washington DC’s web site and see what they say. You could also check the Thai Immigration website (but don’t be surprised if they all say slightly different things! Check the ‘this page was last updated on’ line on any visa information page. They frequently leave very old pages available online).
Thailand - 30 day visa exemption on arrival, 60 days visa if you get it before arrival. One 30 day extension, then you need to do a visa run. You can get pretty much as many single entry tourist visas as you'd like as long as you mix and match the countries you apply for them in. Get a couple in Vientiane, a couple of Penang, a couple in Yangoon and so on. See thaivisa.com for up-to-date information.
Bali - 30 days exemption on arrival. Get a visa if you want to be able to extend an extra month. At the airport immigration desk, the default queue of people all get exemptions. However there is another desk you can go to for the visa (unless you are from Philippines, then you can oddly only get an exemption). There is also a 6 month “social visa” which is relatively easy to get, but you are required to do it at an Indonesian embassy somewhere outside Indonesia. Singapore is a common choice.
Cambodia - 30 days on arrival, 21 days for ASEAN members. Extend it for up to 1 year after arriving.
Vietnam - a bit strict, most nationalities need to get the visa at an embassy rather than at the airport during arrival. Usually 1+ month but it varies. Or you can get a visa on arrival but you need to have printed out an invitation from within Vietnam beforehand. There are many companies that will do that for you, myvietnamvisa.com is one of them and vietnamvisacorp.com are another.
Philippines - 1 month on arrival, extensions up to 3 years. Yes, 3. Years. An onward ticket is absolutely required and they will deport you if you do not have one. The immigration computer checks the airlines and throws up a red flag on the officer’s screen so don’t expect to bluff your way through. I tried and failed, it was a bad time.
Hong Kong - they give quite generous visas to anyone upon arrival. Living costs are high so you probably won't need a long one.
Thailand has become tired and annoyed with people getting back-to-back visa exemptions, so after you do it a few times the immigration people will start to grumble and warn you. During a visa run, you can leave and come back on the same day. It’s smarter (and less risky) to stay out of the country for a couple of days if possible. The good news is that this will kind of force you to get out and explore other countries. It will also give you a brief change of pace and new scenery to help you take a break from work.
Generally you just need to find the quickest/cheapest (or some combination) way out of the country and back.
Common visa run routes are:
- CM - to Vientiane by bus (10+ hours each way so only do this if your time is not worth much), or fly to Bangkok and then anywhere cheap such as Phnom Penh, Singapore (they’re a bit strict on the documentation), Penang
- Koh Lanta - to Malaysia by van or Singapore by plane (via Krabi or Phuket)
- Bali - Singapore or KL
- HCMC - PP by bus.
- PP - Bangkok or HCMC
- Philippines - Hong Kong or KL
Wherever you are you can find the cheapest flight out of the country by using skyscanner.com with the destination set to ‘anywhere’.
Legality of DN life
You are a Tourist. Always.
Legislation of visas has fallen behind the times and there is usually no clear category for people working across borders. Getting a work visa assumes a local employer and getting a business or investment visa requires proof of large amounts of capital. Tourist visa is the only option.
99.9% of people that go through immigration never get asked any questions, especially if they look like tidy responsible adults (few visible tattoos, clean clothes, no dreadlocks).
Whenever filling out a form for immigration, tick the “Tourist” box. If asked about your plans say where you’re going and that you will be sightseeing. Never mention that you work on your laptop; you’re on holiday. If asked about how you manage to support yourself on such a long holiday, tell them you own a business in your home country which you run in a hands-off manner by sending a few emails now and then to the manager. The nature of your business is what you actually do, so you’ll be able to talk convincingly about it.
In Thailand and Philippines you don’t need them, but in most other countries you can save yourself time and trouble by having a visa agent to do it for you. They know the system, what to put on the forms and when/how to grease some palms. Sometimes it's possible to get longer visas with less documentation more quickly than you would be able to alone. Agents are especially common in Phnom Penh, Vietnam and Bali.