Transcribed from The Visitation of London in the Year 1568 (where Thomas is mistakenly called Simon): Barnham. Arms. Quarterly: 1 and 4, Sable, a cross engrailed between four crescents argent; 2 and 3, Azure a pheon argent. (Bradbridge.) Simon Barnham 2 filius. m. — filia — Cressy de London. Filii: Margareta vx. Roberti Conbes de London renupta Thomæ Covill sive Colvill de Chigwell in com. Essex. Augustinus 2 filius. Simon 3 filius. Franciscus Barnham filius et hæres. Maria. Etheldreda vxor Will'i Cleybrook.
Thomas, like his older brother Francis, was a draper, and is also said to have been an alderman. In addition, he was a member of the Guild of the Holy Trinity. During the lifetime of Thomas, there were nine guilds in the town of Wisbech, of which the Guild of the Holy Trinity was by far the most important. It became the main feature of Wisbech life in the later Middle Ages and was the direct ancestor of the Town Corporation. It is reputed to have originated in 1379, the year of the earliest surviving account. Certain entries in the account, however, make it plain that the Guild had already existed for some time before. Wisbech is a municipal borough and seaport, in the county of Cambridge, 90 miles northeast of London. The membership of Thomas in its most important guild suggests that he must have lived in or near the town of Wisbech, where he was undoubtedly an important citizen.
According to Boyd's Inhabitants of London, Thomas Barnham, citizen & band-seller, Eastcheap, freed two apprentices: 1) Richard Osborn, citizen & draper, freed 8 Jul 1576 and 2) Richard Alkin, citizen & draper, freed 21 Nov 1597. Since Thomas died in 1576, the second entry is suspect. Perhaps Richard Alkin completed his apprenticeship under Thomas Barnham the son of Francis Barnham and Jane Inwood.
Thomas had a will, dated 29 May 1576, leaving all his possessions to his widow, Alice.