A recent British Council study calculated English language teaching was worth more than £1bn a year to our economy.
It is surprisingly easy to get your hands on a slice of this enormous pie. And you do not have to live in traditional TEFL* hotspot such as Brighton or Bournemouth.
Read about other ways to make money in retirement.
The different types of arrangement
Essentially there are two types of stay - with differing financial rewards.
The first and undoubtedly easier option is to provide, in effect, bed and breakfast. Good host families for students attached to local language schools are always sought after.
Students attend classes in the morning and undertake activities/excursions in the afternoon. Stays can last from a few days up to several months.
The second type of programme means more work and responsibility - but bigger rewards. One-to-one home tuition stays involve full bed and board and typically 15 hours of lessons on top.
Students sometimes book cultural visits or extra activities — either in lieu of, or in addition to, the lessons.
Stays normally take place during school holidays and anyone prepared to do the whole season could, based on 2007-08 figures, earn up to £5,000 per year.
Better still, under the rent-a-room scheme, the accommodation component was tax free up to £4,250 (based on 2007-08 figures).
Schools tend to demand qualifications from tutors – commonly either a degree of any description or a TEFL-specific qualification or another recognised teaching qualification.
There are lots of other businesses you can start from home. Read our guide for more inspiration.
How to find the work
Interested? For the first option, it is probably best to look in Yellow Pages for any local language schools.
The more lucrative home tuition work can meanwhile take a little effort to unearth. Plenty of organisations have virtually nationwide networks, operating through local organisers. These are self-employed agents who work from home offices, recruiting host families and placing students fed to them by the schools.
Tracking them down can take a little effort. They may not be listed in Yellow Pages, so check out Situations Vacant in your local paper.
January is a peak recruiting month - but adverts can appear at almost any time of year. Use your social networks to ask around about hosting students. And to avoid leaving it to chance, do a web search on 'TEFL' and trawl through the online recruitment databases.
A cautionary note to close on: problems with insurance claims are extremely rare but it is wise to be covered. Check your household policy and if in doubt, talk to your insurance company for peace of mind.
* 'TEFL' is a traditional acronym for Teaching English as a Foreign Language. It is increasingly being referred to as TESOL - Teaching English as a Second or Other Language.