Customs for parcel shipping to St. Helena
You should check with either the Customs department in St. Helena or with your shipping company for up to date Customs procedures before you ship anything over there. This way you can know before you ship what paperwork needs to be attached to your parcel so you can hopefully avoid any delays having the wrong paperwork may cause. Keep in mind that the Customs procedure does include them inspecting your parcel typically so package your goods accordingly (so don't use wrapping paper you don't want undisturbed as an example). Your shipping company should also be able to give you an idea of how much of a duty will be assessed on your parcel if there is to be one so that you can be prepared to pay it in a timely manner. Your package will not be released for Customs and sent out for delivery if you do not pay your duty fees.
Who ships parcels to St. Helena
Thankfully there are a plethora of companies that ship to St. Helena. This works out to your advantage as you, the shipper, get to gather some price quotes from the various shipping companies and make an educated decision based on what they come back with as far as a quote goes. This works much better than only having one or two choices because in those cases the shipping companies have no incentive to lower their prices and make them more affordable to you, the shipper. You should look into FedEx, UPS, USPS and DHL as well as Parcels 2 Go and ISP Parcels. And after you get some price quotes but before yu make your decision, you will want to see what kind of track records the companies have on making timely deliveries as some companies are better at keeping on track, time wise, than others. Also ask about tracking and insurance services as well, which will be an additional cost but may be worth it, depending on what it is you intend to ship over there.