Lawson was trained as a lawyer and largely served the country in the role of ambassador in treaties with England and as King's Council. He served as Town Clerk in Edinburgh in 1482. He was Justice-Clerk from 1489 and was still in post described as Justice-Clerk-General to the King in January 1504/5.[2][3]
Lawson joined with Edinburgh merchants in lending money to James III of Scotland in 1482 and 1488, two crisis years of his reign.[4]
He was one of the counsellors appointed for managing the affairs of James IV. Along with Alexander Home, Chamberlain of Scotland, and others, he was one of the Commissioners appointed to ratify the treaty concluded at Coldstream on 5 October 1488 for a three years' truce with England. On 30 May 1490 he was one of the Commissioners of the King who, with 300 horsemen, had a safe conduct for two months to enter England, remain and return. On the 25th June 1492 he was one of the King's Commissioners who concluded a new 7 year treaty with England, and on 28 July the next year was again a Commissioner in a party of ambassadors to England for 6 months; and yet again on 22 May 1495 he was one of the Ambassadors, with 100 horsemen, who had a safe conduct to England for 6 months.
He was one of the ambassadors of Scotland, who concluded a new 7 year treaty with England, at Ayton, Berwickshire, on 30 September 1497, ratified by King James on 10 February 1498 in the presence of Pedro de Ayala, Prothonotary of the King & Queen of Spain and their ambassador to Scotland.[5][6]
In May 1505, Lawson was acting as Provost of Edinburgh and with the burgh council accepted a receipt from Julian Laci, the factor of the Italian merchant Jerome Frescobaldi, which declared that the former Provost, Alexander Lauder of Blyth had returned all the goods belonging to Frescobaldi which had been in his custody.[7]