In England, do people use "people" or "persons" more? And do you use the phrase "Keep it on your person"?
Person derives from persona, which refers to an individual. People, on the other hand, derives from populum, and it refers to a group of persons sharing a culture or social environment. Person is a singular form, and its plural is persons. Over the time, however, many writers started to adopt people as the plural form of person, and nowadays it is widely accepted. Notice that legal and very formal texts still use persons as the plural form.
People outranks persons by a factor of 30.42 in the British National Corpus. In spoken use the ratio is 167.63 and flicking around before I got asked to register before continuing, the lowest was that there are only 2.84 times as many uses of people in academic works on the topic of law, than there are persons.
Giving ngrams a look, I thought I'd compare not just restricted to the British sources, but also do the same comparison with the American. There isn't much between them, (though one of the problems with ngrams is it goes by place of publication rather than of writing, so this doesn't mean that much, but is still notable if not completely reliable).
I'd note also that there are senses of people that are not interchangeable with persons. (In particular, the senses for which pluralising it to peoples are clearly not).
People would be a group (as in a population, but since the size of that population is not constrained to be a small group) and is more common parlance. Persons is rarely used and where it is, generally refers to members of a population when they are treated as individuals as in "Persons driving a motor vehicle."
"Keep it on your person" is used to ask someone to retain something in case of potential future checks such as a ticket but not often.