Post & Co (P&I) B.V. was founded in 1941 by Mr Jacs Post Jr. He was the youngest son of a large Rotterdam family. He moved to Groningen, a city in the Northern part of Holland, to start an insurance agency on behalf of an Amsterdam underwriting family who wanted to obtain more business from that area. When he started in 1918, he was only 19 years of age. He founded the "Noordelijk Assurantiekantoor", abbreviated as NASK, which became the trade name of the company. By the time the company started to make a small profit, the famous crisis years started and the Amsterdam family lost interest in the company completely. Just before the Amsterdam family decided to sell the shares to a German insurance company, Mr Jacs Post Jr. was allowed to make an offer himself which succeeded.

Jacs Post Jr. was an active man and within short various companies were founded, such as a genuine insurance company under the name Atlantic, a mutual insurance company under the name Eendracht and a survey bureau under the name Inspector. However all along NASK was the most important company within the group. Shortly before the second world war NASK Rotterdam was founded in order to have a good Market placing facility.
In 1941 he founded again a new company this time under the name Jacs Post Jr. and Co and all activities in respect of P & I claimshandling as well as underwriting agencies were transferred and brought together under this company name.

Shortly before the founder of the company died in 1956 the second generation took over the directorship of all companies. This was Sibbert Tj. Post. He was the only son in the family and had six sisters. He started with various reorganizations and decided to sell various activities and concentrate on the two offices of NASK, still in Groningen and Rotterdam, closely combined with what is now Post & Co (P&I) B.V.

The 1960s and 1970s were fantastic years for growth all around the world and at a certain moment NASK alone had a total of 140 employees. In 1977 it was decided to split the activities of the different companies where Post & Co (P&I) B.V. would take over all P & I activities. This was another important step in the company of what is now Post & Co (P&I) B.V.

The third generation started in the family business in 1967 and after a short period the main interest was focussed on Post & Co (P&I) B.V. In 1982 the second generation retired and the third generation by way of Jack Post decided to continue with the Post & Co (P&I) B.V. part from the family business only. Already a couple of years before it was decided by the family to sell the other parts of the company to different recognized players in the Market.

In 1999 the fourth generation by way of Roderick Post joined the company and as of 2005 he forms part of the management of the company, continuing a family tradition and carrying the company forward into the future.