Not the Charity Commission, as they only regulate charities. The Fundraising Regulator might be somewhere to start or Action Fraud. But The Fundraising Regulator ask that you contact the organisation or fundraiser first.
I have previously contacted the fundraising regulator about Jack's Teemill endeavour:
Your complaint about Jack Monroe
Thank you for getting in touch with the Fundraising Regulator.
We have looked at your concerns and for the reasons explained in this email your complaint is outside of our remit.
Our role and remit
Our remit is such that we can only consider complaints about charitable fundraising by registered charities, fundraising organisations, professional fundraisers or other incorporated entities or bodies where
the fundraising is on behalf of a charity or charitable organisation. Individuals, organisations, and companies are free to fundraise in aid of charities or charitable causes, providing that they do not claim to be registered charities, or that they are fundraising at the charity’s behest when they are not.
We understand that Jack Monroe had previously raised money via the sale of t shirts online and had said on this website that the funds were to be donated to a named charity. However, that charity has confirmed that this was not on its behalf, and it was agreed by Jack Monroe that she would no longer fundraise in aid of the charity in this manner. Since then, the website in question now states that any money raised will go to charities – but with none specified.
Independent charitable giving by individuals is usually what is described in the code as ‘in aid of’ fundraising. This means that it is done as an act of giving by the individual, and not officially on behalf of or at the behest of a charity or regulated fundraising organisation. As such, there is usually no responsible regulated charity or organisation we can then consider a complaint against for possible breaches of the code. As there was no formal fundraising agreement between Jack Monroe and any charities to date in relation to the abovementioned t shirt sales, any complaint about it falls outside of our scope to consider.
Next steps
If you are still concerned about the transparency and the charitable claims of the online sales by Jack Monroe, you may wish to raise the matter with Trading Standards. This is because Trading Standards is the relevant body for considering concerns about consumer transactions and businesses and traders making false or misleading claims.