Starting a charity - questions

[Hoofy]

Do you have to register? The idea is simple - I want to provide a service, I don't need funds, it's for people with a particular issue who need help. Can I call the organisation a charitable one or use a term like "foundation" in the name or is there a legal requirement to register (much like I cannot call a business "XYZ Limited" or "XYZ PLC")?

[Hoofy]

Thanks. £5k. I suppose I could work with another relevant charity if someone offers money/donations.