E-Commerce disadvantages can be broadly classified in two major categories:
There can be lack of system security, reliability or standards owing to poor implementation of e-Commerce.
Software development industry is still evolving and keeps changing rapidly.
In many countries, network bandwidth might cause an issue as there is insufficient telecommunication bandwidth available.
Special types of web server or other software might be required by the vendor setting the e-commerce environment apart from network servers.
Sometimes, it becomes difficult to integrate E-Commerce software or website with the existing application or databases.
There could be software/hardware compatibility issue as some E-Commerce software may be incompatible with some operating system or any other component.
Initial cost: The cost of creating / building E-Commerce application in-house may be very high. There could be delay in launching the E-Commerce application due to mistakes, lack of experience.
User resistance: User may not trust the site being unknown faceless seller. Such mistrust makes it difficult to make user switch from physical stores to online/virtual stores.
Security/ Privacy: Difficult to ensure security or privacy on online transactions.
Lack of touch or feel of products during online shopping.
E-Commerce applications are still evolving and changing rapidly.
Internet access is still not cheaper and is inconvenient to use for many potential customers like one living in remote villages.