But the Charity Commission says £5,000?
The threshold above which a charity needs to register is £5000 – this will include many Churches Together Groups. Under this threshold, the charity is exempted. Many churches (but not all) are excepted and do not need to be registered or submit an annual return – this includes LEPs in which at least one participating church is excepted. However, above the threshold of £100,000 churches which are excepted (and LEPs) need to register.
See Excepted charities - GOV.UK for details.