This supplier is based in the Netherlands. I have purchased several aroma chemicals from this source and have nothing to complain about. They sell various alcohols and oils. You can also purchase equipment and packaging for your perfumes. They ship on Wednesdays.
Omikron is based in Germany. They sell a small amount of aroma chemicals some of which can only be sold to organisations and will not be surrendered to individuals. They also sell essential oils and resins. I use this supplier and haven't had any bad experiences.
Dragonspice is based in Germany. I buy from them regularly. They have a varied selection of essential oils and resins as well as a large selection of biological materials. They also sell biological ethanol which is known as Weingeist in Germany. This is non denatured.
Meine Kosmetik is based in Germany. They sell some useful things but nothing you can't buy from alternative suppliers. They sell a small amount of essential oils. I can't comment on the quality. You can also purchase biological weingeist which is not denatured.
Rest of the World
Plush Folly is based in England. The sell essential oils, aroma chemicals, good quality perfume bottles and perfumers alcohol.
Olfacik are based in England. They are a supplier of aroma chemicals. I have purchased items in the past and have nothing to complain about. They ship on Fridays.
This supplier is based in the US and sells both naturals and aroma chemicals. They also sell bottles and blending tools.
The Perfume Supply House sells both naturals and aroma chemicals. They are based in the US.
Perfumers World are based in Thailand. They sell both naturals and aroma chemicals. They also sell formulas, provide learning material and offer courses in learning how to make perfume.