There was a period when I was an individual freelancer, without having formed a proprietorship or something and without having official certificates of experience. Though I made it, after sometime I dropped freelancing and returned to a regular job.
Generally, during interviews people praise the fact that you are self driven, as you have been freelancing. However, when HR folks calculates pay packages, I think they use it as an excuse and define my freelancing period as years without relevant experience. So, it looks like it's as big a disadvantage as not having a job during that period.
What is expected as career experience from freelancing years? How do you appropriately present that experience to potential recruiters?
Just as suggested by people, there has been a good tech project i had done which was also listed in resume. I had international publications out of that work as well. And i was critically evaluated on that very project because that was most relevant work they had got unlike any other candidate.
I think my direct bosses did understand the value of my work and depended on me critically; but HR only used this as an excuse.