This depends on what type of charity you are and what the level of your gross annual income is.
All Charitable Incorporated Organisations have to be registered regardless of the level of their annual income.
Every unincorporated charity with a gross annual income of £5000 or more is required by law to register with the Charity Commission. Once a Charity reaches the threshold it will be required to register in the next financial year. If its income falls below the threshold in subsequent years it will still remain on the register.
A charity below the threshold may enjoy some of the benefits of being a registered charity without the need to be registered. It can apply to HMRC for tax relief and although unregistered, it is still legally a charity and must comply with charity laws.
Being a registered charity makes it easier for your charity to raise funds from the public, grant-making trusts and local government; represent and help the needs of the community and gives donors and beneficiaries confidence that your charity is legitimate and working within a regulatory regime.
All charities benefit from a number of financial advantages, including exemptions from income or corporation tax on some types of income; capital gains tax stamp duty and inheritance tax on gifts made in wills.
It is important to obtain good advice and to understand the regulatory requirements of being a registered charity. A lot of helpful information is available from the Charity Commission at www. charitycommission.gov.uk