an individual registered on a UK electoral register, including overseas electors and those leaving bequests
a UK-registered company which is incorporated in the UK and carries on business in the UK
a Great Britain registered political party
a UK-registered trade union
a UK-registered building society
a UK-registered limited liability partnership (LLP) that carries on business in the UK
a UK-registered friendly or industrial and provident society
a UK-based unincorporated association that is based in and carries on business or other activities in the UK
You can also accept donations, but not loans, from certain types of trusts, certain public funds and from anyone who is paying for the reasonable costs of a visit outside the UK.
Charities are not allowed to make political donations under charity law, even if they fall into one of the categories of permissible donor.
If you know that a donor is a charity, you should make sure that they get advice from the Charity Commission before giving a donation.