De or het lumpsum?

The correct Dutch article is:

de lumpsum

Exception Words ending in -um and -ium usually take het, but lumpsum is an exception. See the rule
Meaning (Dutch) de financiering van scholen door de Nederlandse overheid

How to use lumpsum

the lumpsumde lumpsum
this lumpsumdeze lumpsum
that lumpsumdie lumpsum
our lumpsumonze lumpsum
your lumpsumjouw lumpsum
every lumpsumelke lumpsum
which lumpsum?welke lumpsum?
a big lumpsum / the big lumpsumeen grote lumpsum, de grote lumpsum

Dutch words starting with lumpsum

lumpsumbekostiging | lumpsumfinanciering

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).