Themba was admitted as an attorney in 2007. He then joined JKL Ikaneng Attorneys as a professional assistant in the Civil and Commercial Litigation Department in 2007. In 2008 Themba decided to practise for his own account under the name and style of Serei Attorneys.
In 2011 Themba joined the Legal Division of the South African Revenue Service(SARS), specialising in Tax. While at SARS his duties entailed providing legal support to all divisions within SARS, training all staff members in complex tax law matters, representing the Commissioner of SARS in all litigation matters involving the Commissioner, drafting of settlement agreements between the Commissioner and Taxpayers, assisting other divisions in complex tax matters and drafting of legal opinions, non-binding and binding rulings.
Themba was also nominated to conduct criminal prosecution on behalf of the National Prosecution Authority in terms of Section 22 (8)(b) of Act 32 of 1998; for offences in terms of Section 75 of The Income Tax Act 58 of 1962.
Themba has also facilitated alternative dispute resolution proceedings between the Commissioner of SARS and the Taxpayer, as well as represented the Commissioner in business rescue proceedings and in all liquidation/sequestration proceedings.