Hi Dave, the following is from the Inland Revenue's web site - I'm sure they wont mind.
Employed or self-employed?
Employed
If you can answer 'Yes' to the following questions, you are probably employed.
Do you yourself have to do the work rather than hire someone else to do it for you?
Can someone tell you at any time what to do or when and how to do it?
Are you paid by the hour, week, or month? Can you get overtime pay?
Do you work set hours, or a given number of hours a week or month?
Do you work at the premises of the person you work for, or at a place or places he or she decides?
Self-employed
If you can answer 'Yes' to the following questions, it will usually mean you are self-employed.
Do you have the final say in how the business is run?
Do you risk your own money in the business?
Are you responsible for meeting the losses as well as taking the profits?
Do you provide the main items of equipment you need to do your job, not just the small tools many employees providefor themselves?
Are you free to hire other people on your own terms to do the work you have taken on? Do you pay them out of your own pocket?
Do you have to correct unsatisfactory work in your own time and at your own expense?
In summary, if you take staff on they will be employed whether for 3 hours a week or 40. If they only do 3 hours a week it is unlikely they will need be eligable for NI unless they have another job which takes their earnings over £89.00 per week.
For 3 hours a week is it really worth their while to go through the arduous process of raising and submitting invoices to you and completing the Self-Assesment form?
Is that easy enough?
Musicman