When are you hoping to start??
I think the first task is to get the green light from potential supervisors, they you will have to formally apply. On the application form (UK PhDs), you will be asked how you will fund it and if you are looking for funding, to confirm what funding applications you are making. Each uni should have info on funding applications, etc., unless you are applying to a programme with funding already secured. I think it is entirely your choice as to what you tell potential supervisors re funding, but it will be explicit on you formal application, either way. Although I'm sure you're already aware AHRC open funding, Uni scholarship competitions, etc usually open in the Autumn and are decided early Spring. A few carry on later, but not many...
Good luck.