Daniel Ainsleigh's reply:
It’s not really possible to be black and white in this question but I’ll try to keep it as short and clear as possible.
You don’t need any qualifications to call yourself an actress. Where qualifications come in handy is that they may qualify you in the eyes of other professionals -they are certainly a reassurance to many agents and casting directors who may have limited time or information upon which to make a decision about working with you. The greatest benefit of completing an DramaUK (the new name of the NCDT) accredited course is that it should make you a considerably better performer. It would also arm you with technical skills and a certain knowledge of how the profession and business works. In short, there is no better route into the profession, no better training ground and no better launch pad towards winning representation with a good agent than an DramaUK accredited course. Take a look at www.dramauk.co.uk for accredited courses.
If this isn’t possible for logistical or financial reasons then you should consider working with a professional acting coach who can offer something more intensive. There are tons of them around but some are better then others. Check out www.actingcoaches.info
So, in short, no you don’t need to do an HND in Acting, but it might benefit you greatly to do it!
Actor and Acting Coach