The conditions under which barter system work are:
(i) Each person should have surplus stock. Only then he can exchange it with anomer person's surplus stock.
(ii) For the exchange of goods face to face meeting is essential.
(iii) The needs of both parties should coincide. Each party should be willing take other parties offering otherwise exchange will not take place.
Eg. If Murugan has surplus rice and Ganesh has surplus wheat. Unless Murugan is willing to exchange rice for wheat, bargain will not take place.

The important Ancient Trade centres in the coastal regions of Tamil Nadu are:
(i) Alambarai
(ii) Alagankulam
(iii) Pumpuhar
(iv) Marakkanam
(v) Vasavasamudram
(vi) Mylapore.

The role of the State in trade related to two aspects namely adequate infrastructure to sustain the trade and administrative machinery for taxation. During the Sangam period, the main trade routes were passing through thick forests over western ghats. The State protected the merchant caravans on these trade routes from robbers and . Main roads known as Peruvali were built far surface transportation. Besides state expanded infrastructure for shipping such as ports, lighthouse, warehouse etc., to promote overseas trade.

The important Ancient Trade centres in Tamil Nadu are:
(i) Alagankulam (Ramanathapuram),
(ii) Mylarphan (Mylapore, near Chennai),
(iii) Keberis (Kaveripumpattinam),
(iv) Poduke or Poduce (Arikamedu, Puducherry),
(v) Soptana (Marakanam),
(vi) Nikam (Nagapattinam),
(vii) Periyapattinam, .
(viii) Kayalpattinam,
(ix) Colchi (Korkai),
(x) Comari (Kanyakumari).

Trade and commerce was so common to Pandya Dynasty. Information collected from the diaries of foreign travellers, voyagers, mariners and adventurers of the ancient world highlighted the prosperity of trade in the Pandya country. The Hebrew and Latin literature, Archaeological remains in Aden, Alexandria, Java, Sumatra, and even China add support to the fact of existence of trade network in the Pandya country. Trade in copper, cloth, salt, flower, sandalwood, fish, paddy, cereals, pearls, etc., flourished during their period.

In a technology driven society today again the course of commerce activities is heading for a cashless system through e-commerce which means business activities enabled through electronic modes like Online trading, Mobile banking and e-marketing.

The whole of commerce activity has emerged from barter system into a multi- imensional and multifaceted scientific system consisting of courses like Monetary system, Mail-order business, Hire purchase system, Instalment purchase system and so on.

1. Each party to barter must have surplus stocks for the trade to take place.
2. Both buyers and sellers should require the goods of each other deseperately i.e., double coincidence of wants.
3. Buyer and Seller should meet personally to effect the exchange.

The place where the goods were sold was called "Angadi".Day market was called as Nalangadi while the night market was called as Allangadi according to St.PoetIlangoin Silapathigaram, Madurai-Kanchi.

(i) Hindrance of finance :
(1) Producers and traders may not have the required funds at the time of their need.
(2) Banks and other financial institutions provide funds and help in transfer of funds to enable the functioning of business smoothly.
(ii) Hindrance of developing the exact product :
Research and development helps in developing the exact product or service which can satisfy the specific wants of consumers and thus improve the standard of living of the people.
(iii) Hindrance of both selection and delivery doorsteps :
E-Commerce enables the consumer to select the product in the website, place online orders and make payment after receiving the product at the door step.