Dear K’ Siriporn,
I regret to say that I have chosen to order standard gas with other company.
For PTT process of verifying std gas, it sometimes takes long time to accomplish. This will lead your company not to satisfy of long waiting time to send invoice to PTT.
However, PTT verifying process would be improved in next 2-3 years. Then, we will probably order your std gas again ka.
PS. I know that companies once send the goods to customers, the companies expect to send invoice at the same time. But just for this case, PTT have to verify first, then invoice will be sent right after done verification.
The period of verification takes long time. So it’d better choose other company whom can wait for long period. However, if you could stand PTT process, we would order std gas next time.