private expense; personal funds; one's own expense
Refers to money paid from a private individual's own resources rather than from public funds, an organization, or an employer. Often used as 私費で, meaning “at one's own expense.”
She studied at a university overseas at her own expense.
その資料は研究者が私費で購入したものだ。
Those materials were purchased by the researcher with personal funds.
He put his own money into the research.
It was decided that the trip's expenses would be covered from personal funds.