Stephen McLaughlin claimed he was a “shipping agent” and did not ask about the cargo.
One man, 40-year-old Meet Singh Kapoor, died in the crossing from Belgium to Tilbury Docks, Essex, where the migrants were found in August 2014.
Four men are on trial at Basildon Crown Court for conspiracy to smuggle people.
All of them deny the charges.
Mr McLaughlin, 34, of Limavady, told the jury: “I just booked the container. I didn’t ask what it was for – nobody asks what’s being carried. The shipping agent never asks that question.”
Those inside the container, Afghan Sikhs aged between 16 months and 72, were found on 16 August after docks staff heard noises coming from inside the container.
When they opened it, they found the people inside distressed and struggling to breathe.
They were hidden amongst barrels full of a liquid which may have been intended to look like alcohol, the court heard.
Earlier, the court heard from fellow defendant 47-year-old Martin McGlinchey, of Derryloughan Road, Coalisland, who took the container to Dover before it was transported abroad.
He said he believed it would be used to carry vodka, and was unaware it would be used to transport migrants.
Mr McLaughlin told the court he knew Mr McGlinchey had been involved in alcohol smuggling but was “not that interested” because it was commonplace in the haulage industry.
Mr McLaughlin, Mr McGlinchey, Timothy Murphy, 33, of Elmgrove, Derry and Taha Sharif, 38, who is Kurdish and lived in Tottenham, London, all deny conspiracy to facilitate illegal entry into the UK.