De or het certificeringsinstantie?

The correct Dutch article is:

de certificeringsinstantie

Rule Words ending in -tie and -sie: almost always de. See the rule

How to use certificeringsinstantie

the certificeringsinstantiede certificeringsinstantie
this certificeringsinstantiedeze certificeringsinstantie
that certificeringsinstantiedie certificeringsinstantie
our certificeringsinstantieonze certificeringsinstantie
your certificeringsinstantiejouw certificeringsinstantie
every certificeringsinstantieelke certificeringsinstantie
which certificeringsinstantie?welke certificeringsinstantie?
a big certificeringsinstantie / the big certificeringsinstantieeen grote certificeringsinstantie, de grote certificeringsinstantie