De or het overstapregeling?

The correct Dutch article is:

de overstapregeling

Rule Words ending in -ing: almost always de. See the rule

How to use overstapregeling

the overstapregelingde overstapregeling
this overstapregelingdeze overstapregeling
that overstapregelingdie overstapregeling
our overstapregelingonze overstapregeling
your overstapregelingjouw overstapregeling
every overstapregelingelke overstapregeling
which overstapregeling?welke overstapregeling?
a big overstapregeling / the big overstapregelingeen grote overstapregeling, de grote overstapregeling