Lesley Dewhurst, co-director of the charity based in Manzil Way, East Oxford, said staff need to bring in fundraising of about £300,000 a year.
Ms Dewhurst said the charity received up to £1.3m a year funding from Oxfordshire Clinical Commissioning Group but that is not enough to cover the cost of the work it needs to do all year round.
She added: “Our income from the Oxfordshire Mental Health Partnership contract is £1.15m a year but our total expenditure is £1.6m.
“Some of that shortfall is covered by sales from our two cafes and our shops.
“However, we have approximately £300,000 to raise each year.”
Ms Dewhurst spoke out after Restore was named the winner of The Oxford Times Charity and Community Award at the Oxfordshire Business Awards earlier this month.