Duty of payer incase of payee is covered under 172

Respected Experts,

Good Morning to all,

I have a one query, i hope here i can get the answer.

Company (A Ltd) paying Ocean freight charges to a shippling company (say B Ltd, which is registered outside india and this company does not having any perminent establishment in india).

As per section 172 (it has overide effect on entire income tax act), if any non resident shipper getting revenue he has to pay 7.5% as.... so and so......... 

as i said above this section 172 has override effect on entire income tax act (including section 195)......

How A ltd will ensure that, B ltd is complied with section 172 before making any payment to B ltd ????????

Thanks