The distances are short and the borders are not
Because the hops are short, people underestimate how many operators they will touch. A single week can involve three separate national networks, each with its own visitor tariff.
This is the region where the difference between a country plan and a regional one is least about price and most about not having to think at every checkpoint.
Why overland crossings catch people out
An airport arrival is a clear signal to buy something. A land border rarely is. The bus keeps moving, the signal reconnects to a different network, and the charge starts without anything on screen telling you it has.
If you are travelling this region by road, decide your connectivity before the first crossing rather than after the first bill.
What coverage looks like on the ground
Capital cities, the Pacific coast resorts and the main highways are well served. Coverage on the Caribbean side, in the highlands and in the smaller inland towns is thinner and inconsistent between operators.
Costa Rica and Panama are generally the strongest. Rural Guatemala, Honduras and Nicaragua are where you should expect to be offline for stretches.
How to decide
If your trip is one country, buy for that country. If it is the classic overland route, the regional plan is doing the thing it was designed for.
And as everywhere, check your handset is not carrier locked before you fly. It is the single most common reason a perfectly good profile refuses to install.
Where are you going?
DestinationsCommon questions
Do I need a separate plan for each country?
Only if you insist on buying locally. On a multi country overland route that means several purchases in two weeks, which is exactly the case a regional plan answers.
Is roaming charged at land borders?
Yes, and usually without any obvious signal that it has started. Land crossings are the main reason bills surprise people in this region.
Which countries here have the best coverage?
Costa Rica and Panama, generally. Rural areas of Guatemala, Honduras and Nicaragua are the thinnest.
Is a regional plan good value for a one week trip?
Only if that week crosses borders. A week in one country is a country plan.