Correct spelling


Correct spelling, explanation: expense is a word of Latin origin as it comes from the word expensa. In the process of assimilation to the English language, the word lost the characteristic Latin a at the end which changed to e. Besides that, the form did not change much, so expense remains the only correct form.

Definition of expense:
1. The number of means (usually financial) required to do something
The company paid all expenses of the office party.
The expense of living alone is higher than I ever thought.

Idioms with expense:
at the expense of – at the cost of (figurative and literal), usually implying negative experiences/consequences.
He used to eat a lot of fast food at the expense of his health.
The country could improve the healthcare sector, but only at the expense of underfunding other sectors.

Incorrect spelling


Incorrect spelling, explanation: expence would be pronounced the same as expense which may lead to errors. This is not the correct word, because of the origin of the correct version – expense. Because of its Latin origin (expensa), the word does not need a change of s to c.