The amount I calculate is Fix rate at 167,980.18 all year, but in fact his salary adjust on May, so the income Tax will be less than 28,870.05/month. However we can use this figure send to the Revenue Dept. then we will get refund back approx. 20,000 baht at end of year.
For 2017 Khun Pawel have to pay Tax by himself so the figure was correct, he should be received some refund from SSO and PF approx. 2,000 baht at end of year.
Further assistance please do not hesitate to let me know, thank you very much for kind support.
Best Regards,