Teaching English is one of the few jobs which you can do locally in a foreign country without a lot of training which doesn’t compete with the local labor pool, since the locals typically aren’t native English speakers required for this type of work.
This makes work visas for English teachers relatively easy to obtain since it’s easy to prove that there aren’t more qualified candidates available locally. This type of work can also be attractive as a semi-retirement job because often you can negotiate to work part time, giving you more time for other things you’d like to do.
The education requirements for ESL teachers vary by country. A BA or BS degree is preferred in all countries, but some countries, particularly in Latin America and SE Asia, will hire teachers without degrees. Most countries expect you to interview (often via Skype) and obtain a work visa in advance, but some countries, again mainly in Latin America and SE Asia, prefer you to enter the country on a tourist visa and interview there and then apply for a work visa locally once your employment is secured. The Middle East is the most demanding in terms of educational requirements with an MA preferred in many countries, but the pay is higher there as well. Many countries in Europe require EU citizenship in order to teach there, which would exclude US and Canadian citizens from applying. I assume this means that they employ a lot of teachers from England and Ireland. A few European countries have special programs which will hire graduating US college students to work as language “assistants” in grade schools. Spain has a program like this which our eldest daughter participated in for two years teaching in Madrid. Unfortunately, that doesn’t help us older people.
This website has a nice table which show the education and visa requirements for many countries, as well as contract and salary information.
In addition to a bachelor degree (or in place of it, if you don’t have the degree) you will want to get a TESL certification to show potential employers that you have some knowledge about how to teach English as a second language. The two most respected certifications are CELTA (certified by the University of Cambridge) and the Certificate in TESOL from Trinity College London.
The price of TESL\TESOL courses typically range between $1000 to $2500 and most take 3-6 weeks to complete. The online courses tend to be on the cheaper end of the scale but are also less valuable. Make sure the course is accredited by a respected institution and that it will be accepted worldwide. The course should have 100+ hours of instruction and include real supervised teaching practice
Another great website with active forums which have a lot of information on TESL certification programs and how to get jobs in various countries is Dave’s ESL Cafe.
Unfortunately, one of the problems you will encounter as an older worker trying to get TESL jobs is age discrimination. In some countries, the problem is a bias against hiring older teachers. In other countries the problem is with work visa restrictions. If the country has a mandatory retirement age of 60 or 65, often the country will not issue work visas to people over the retirement age. This website has a table of age limits for work visas in various countries.
As you can see, even though this list is missing many countries, a number of the countries listed cut off work visas at age 60. You should check each country you are considering working in to make sure that you will be able to obtain a visa to work in that country. Here is another article which talks about this issue and is a bit more encouraging.
The general feeling I get from reading the various TESL websites is that people over 50 will find it much more difficult to find TESL jobs, but there are lots of jobs available so just be persistent. Several people recommended going to countries where you have to apply for jobs directly from within the country rather than applying from your own country. The argument is that it is more difficult to say “you are too old” when you are sitting in front of them, and, since teachers are always in demand, they may be more willing to hire someone who is already there and available.