If you've had a good month I can see the temptation to take those figures and multiple by 12. However, it's not as simple as that, unfortunately. Your run rate is a financial prediction based on your current performance. So, it would be reasonable to plot your performance over the last year (or two) and use that to extrapolate likely future trajectory.

It is always exclusive of VAT.

If you have latest quarter revenue figures you can just multiply them with 4 or you can multiply the monthly figures by 12 to get annual run rate.