Starbucks coffees do not contain any forbidden ingredients or alcohol, thus qualifying as halal. When making pastries using fat from sheep or cows that has been slaughtered according to Islamic rules, however, must adhere to strict halal standards in order for the recipe to remain halal.

JAKIM is the official organization in Malaysia responsible for monitoring and certifying food and beverage establishments that adhere to Islamic dietary laws, so those following strict halal guidelines should always patronize eateries that have been officially certified halal.

At this writing, Costa Coffee does not currently possess a JAKIM certification; however, they may have applied or be in the process of receiving one recently. Therefore, for updates regarding this matter it would be best to contact them directly through their official website or social media accounts; alternatively you could visit one of their offices locally.