It was not easy because of the protectionism that dominated international trade at the time. Difficult negotiations were required, and the Finnish negotiating position as a small nation was not strong. The first trade agreement between Finland and the UK was signed in 1923. It was very successful by any standard.
During the inter-war years, Britain became Finland’s most important market by far, taking about half of our exports. Finnish foreign trade during the inter-war years was so concentrated in Britain that in economic and financial terms Finland was clearly in the British sphere of influence.