unpaid for

References in classic literature ?
He left his rent unpaid for three weeks, explaining to his landlady that he would get money at the end of the month; she did not say anything, but pursed her lips and looked grim.
OVER the last few weeks much has been written about the role of 'carers'- those who provide care in a paid capacity, 'care support workers', and those who care unpaid for a friend or family member who due to illness, disability, a mental health problem or an addiction cannot cope without their support.
British Airways has announced that almost 7,000 of its workers have applied for voluntary pay cuts, including 800 who said they will work unpaid for up to a month.
ALMOST 7,000 British Airways staff have applied for voluntary pay cuts, including 800 who said they will work unpaid for up to a month, the airline announced yesterday Of the 40,000-strong workforce, 6,940 employees had volunteered for unpaid leave, part-time working or unpaid work by June 24, which the company said will save up to pounds 10 million.