The global Customs community is becoming increasingly harmonised. But please be cautioned about the use of a tariff heading on an invoice.
[This will certainly get the attention of Customs officials who like to stop such consignments.]
As an importer or exporter of goods you may be tempted to insist that the tariff heading should be reflected on the commercial invoice. While there is nothing wrong with this, it is not a mandatory Customs requirement. Not in South Africa in any event.
The World Customs Organisation established the Harmonised System for the global classification of goods at a six digit level. Countries which work at an eight or ten digit level do so independently. Headings at eight (South Africa) or ten digit levels do so in order cater for domestic tariff and regulatory requirements.
While headings are globally harmonised at a six digit level, this does not mean that classification will always be identical from one country to another. A product recognised under one heading in South Africa, might be tariffed within a different tariff heading in Germany for example.
The simple reason for this is that different people see things differently. This is exasperated by classification in different countries in relation to culture, language, education, technological advancement in some countries (or a lack thereof in others), and so forth. Tariffing at an eight or ten digit level, (which adds to the complexity of the tariffing process) may in itself be the cause of differing opinions.
Because inconsistencies in the tariffing of goods from one country to another do exist, headings may occasionally be misaligned. This will certainly get the attention of Customs officials who like to stop such consignments. The status of your tariff headings will depend on how you manage the tariffing process with your supplier or consignee.
Again, there is nothing inherently wrong with having a tariff heading on a commercial invoice, so long as the classification process is managed well.