The easiest way to pay is online. The service accepts all major cards as well as PayPal. Paying this way gives you immediate access to the course.
But if you need to pay via invoice, then no problem! Just send an email to
mrbartonmaths@gmail.com with details of:
1. The email addresses of the delegates taking the course
2. Your school name and address
3. Who to email to invoice to
Then I will send you an invoice and register your colleagues on the course.