Small business switching to subject to VAT

You only have to start charging VAT when you become subject to VAT. So from that moment on, you adjust this in your account. And submit a return for Q3?

And you still have three days to submit it, if I'm not mistaken, so that's good ;)

Yes, for Q3 I now have a combination of invoices without vAT and invoices with vAT. I'm not entirely sure whether I should just file my return with the income from the invoices with vAT, or whether I should also take into account the month (July) in which I was still a small business.

And yes, by late submission I meant my application to become subject to VAT. Because that didn't happen until 1 August and not 1 July at the start of the quarter, there would be a penalty. But FPS Finance isn't answering me, so I'll try to get some clarity within the next three days :)