What is the difference between PLA and IEFP courses?
They are not alternatives to each other. PLA, Português Língua de Acolhimento, is the national programme. IEFP is the public employment and training agency that coordinates it nationally. The courses themselves are delivered by a network of training entities around the country, and the entity must be DGERT-certified for the certificate to count.
Three different things with three different jobs
People treat PLA and IEFP as two competing routes, and then get confused when the answers overlap. They sit at different levels.
PLA is the programme. It is Portugal's state-funded Portuguese training for immigrants and refugees, built around integration rather than language alone, and funded from the Portuguese state budget together with the European Social Fund and the Asylum, Migration and Integration Fund. That public funding is why places can be free.
IEFP is the agency. The Instituto do Emprego e Formação Profissional coordinates the programme nationally. It is where many people register, which is why "IEFP course" is often used as shorthand for the whole thing.
The training entity is who actually teaches you. Courses are delivered by a network of providers across the country, not by IEFP directly.
The part that decides whether your certificate works
The training entity must hold current DGERT certification. That is what makes the certificate it issues valid proof of language proficiency for a citizenship application.
A certificate from a provider without that certification may not be accepted. This holds whether the course reached you through IEFP, through a municipality, or privately, and it holds whether you paid nothing or paid well. Ask for the certification number and verify it before you enrol.
What this means practically
Asking "PLA or IEFP?" is the wrong question. The useful questions are: is there a place available to me, on a schedule I can actually attend, with a DGERT-certified provider?
If the answer is no on availability or schedule, a private PLA course or the CIPLE exam are the routes that remain. We prepare people for the reading part of the CIPLE, and we neither run courses nor issue certificates.