Two-thirds of funders do not communicate with their beneficiaries before providing funding, according to a report on grant-making trusts produced by the consultancy nfpSynergy.
The report says that 68 per cent of funders do not talk to beneficiaries before granting funding and 65 per cent do not communicate with them after providing funding.
The lack of communication is "a genuine burden" for many charities, the report states.
The report adds that 44 per cent of beneficiaries are unlikely to tell their funders if they have a problem with them.
The findings come from existing studies of the grant-making process, including the report Listening for Change: Two Sides of the Same Coin, produced by the Blagrave Trust earlier this year.
The average individual grant size in the UK is approximately £10,000, the report says, and there are 8,000 grant-making trusts in the UK giving about £3bn annually.
The geographical distribution of UK grants correlates with charity density rather than deprivation levels, the report says, which means that Greater London receives 30 per cent of all regional funding in England.
In comparison, only 7.1 per cent of regional funding goes to the north east of England despite there being similar levels of deprivation to Greater London.
The Bill and Melinda Gates Foundation is the largest grant-giver worldwide and the Wellcome Trust is the second-largers, the report says.
A further study on grant-making trusts is expected be released by nfpSynergy later this year.