@pyrhonn Ok?
OP' is asking if they can charge from their corp. This ask/act makes sense if OP is seeking to not exceed that 30k amount on their sole prop/individual situation and has not done the hst registration for their sole prop structure.
I am very doubtful that OP is seeking to...
@coolbutclueless You can invoice from your corp if this is what you are asking. Re-submit your writeup/contract and charge your HST. If you didn't quote HST on your original contract then eat the slight loss and make the contract price inclusive of hst.