It really depends on the firm and the region/country.
Like Sidi mentioned, BCG used to have this same pay per level structure, e.g. 1st year consultant and 2nd year consultant are paid the same salary, and only get salary increase when consultant gets promoted to Project Leader. Same for PL to Principal. During my time there, I got the same pay within the 2-year windows. However, recently BCG SEA has changed that to a year-on-year pay increase. Although the year-on-year increase in the role would be much smaller compared to the increase when you get the promotion. I know that Bain SEA has been giving year on year increments as well nowadays.
When you get promoted, in the previous pay scheme, it would be almost 50% from Associate to Senior Associate, 33% from Senior Associate to Consultant, 25% from consultant to PL, 20% from PL to Principal. The % is higher for junior roles because the base is smaller.