There are some differences when it comes to parcel versus document deliveries conducted by courier companies in Singapore.
First of all, there are companies which specialize only in document deliveries. These are usually very small companies with only a handful or fewer couriers in the company and they use bikes to operate. This is because bikes are cheap in Singapore and they are more than enough for document deliveries (as these documents can be put within the enclosed containers at the back of motorcycles. Take note that some companies only hire couriers on bikes for document deliveries, so make sure to find out and clarify this point first if you need to deliver a bulky parcel or item.
Next of all, there are courier companies like PCA which provides both local document as well as parcel deliveries. Usually, most companies which provide parcel deliveries are able to provide document deliveries also, but not vice versa. That is why a parcel delivery company like PCA Masters or Regent Courier Service are able to grow much faster than those which just depend on motorbikes. (Of course, it is within reason. A general logistics company will be using large lorries and trucks and will not bother with moving small parcels or documents for individuals.)
Generally, parcel deliveries in Singapore are more expensive than that of document courier services. This is simply because van drivers usually cost more to hire and they can take fewer deliveries per day as they are not able to navigate in traffic as quickly as motorcyclists can. Additionally, vans cost more to lease or purchase as well relative to motorcycles.
In short, do not be surprised if you get charged rather significantly different prices if you were to deliver a parcel instead of a document. This is simply like the pricing differences between delivering a small item and a really bulky item. Just like how furniture or house moving services in Singapore generally cost a lot more than parcel deliveries, parcel deliveries also cost more than document delivery services in Singapore. It’s just that simple.