Hi! Im from Finland and we have both open classes and different categories, the rules go quite well hand in hand with FEI rules.

Open classes on a club to national level are: easy D(only walk and trott), easy C(all gaits), easy B, easy A, advanced B and advanced A, then it goes to international classes (inter, st george, gp etc.). We also have different categories: Childern, Ponies, Juniors, YR and Seniors (im not sure if we have U25), in these categories we either use FEI tests or national tests, depending on the level of the competition (club/regional/national). Usually riders start at easy C and work their way up but you can compete all the way to regional level easy A without having to qualify. I’m a show jumper/eventer so im not too invested in our dressage rules😄

Hi! I'm from Portugal, here we have 4 levels before the international levels (St George and Grand Prix)!
Each level has 3 tests that we do along the season, the test 1 is easier then test 3.
Preliminary (P) - is for 4 yo horses, is very simple test, it has the 3 gaits.
Elementary (E) - is for 5 yo horses, it has some halts, leg yielding and rein back
Medium (M) - is for 6 yo, it has some shoulder in, half pass (in the test 3) and some transitions from canter to walk
Complementary (C) - for 7 yo, it has flying changes and some exercises preparing for St George!
Usually less experienced riders start on the P level and go up!
Hope it answers

Hi Juliette 😁
In Poland it’s divided into various degrees of difficulty from the easiest to the most difficult.
L class- those programs are very easy. You have to present walk, medium walk, working trot, volte.
P class- the same as L and also side walk, extended trot.
N class- the same as L, P but here very important is collection of horse. There are some figures like pirouette in walk, halfpas, extended trot, counter canter.
C class- apart from figures from previous classes there is also flying changes. The most important is harmony, arched horse’s back and the lightness of the figures.