If you are buying tea in bulk, packing it down and reselling it, you will need to be aware of the weights and measures regulations. This applies whether you are selling tea on in retail form or simply wholesaling from larger amounts.
Labelling is the other aspect of the weights and measures regulations. You will need to give a weight of product within your packaging, not counting the packaging itself.
For a UK-based business, this declared weight will have to be in the metric system, most likely grams for packets of tea. It is a myth that you are not able to use imperial units - these can be listed as well, with equal billing to the metric measurement if you want.
There are two ways to make sure you are compliant with the weights and measures rules when packing products. One system is the minimum weight system - you have a system in place that guarantees you are always packing at least the declared amount. From a legal standpoint, it is fine to overweigh and have more product in a package than your customer is expecting.
The other option is the average system, where your process ensures that a production run averages above the declared weight. To follow this system, you will need to make sure your packing system meets these requirements:
If you can demonstrate this with a random sample from a production run and have records in place to show it, you will meet the requirements. Using the average system also has the advantage that you will be able to use the ℮ mark on your labelling. Products that carry the ℮ mark can be exported throughout the European Economic Area without you having to find out about and check your compliance with whatever local weights and measures requirements there might be in each country.