No reasons were given for the changes, although they come amid growing calls for more reforms in the government’s taxation system from members of the private sector in Tanzania and both Bretton Woods Institutions - the World Bank and International Monetary Fund (IMF).
The president's office said in a terse statement that Magufuli had “annulled the appointment of the TRA board chairman … and dissolved the board."
A new board chairman and members will be appointed at a later date, it added.
In a separate statement issued by State House later yesterday, it was announced that the president has also appointed Charles Kichere as TRA deputy commissioner general.
Kichere is a former employee of the Tanzania National Roads Agency (TANROADS).
When contacted by The Guardian for clarification, State House director of communications Gerson Msigwa could not explain the sackings, saying only: “The reasons are best known to the president himself...I was simply directed to inform members of the public about the decision.”
Mchomvu, a well-respected former senior civil servant, was appointed chairman of the TRA board by then president Jakaya Kikwete in 2011, for an initial three-year term before being re-appointed to the same post in 2014.
He was scheduled to end his second term – the maximum allowed - as board chair in 2017, only to now be sacked before completing his tenure.
He has over 30 years of experience working in government, serving at different times as permanent secretary in the ministries of defence and national service, industries and trade, and home affairs.
Mchomvu has also in the past either chaired or been a member of boards of directors for various other entities such as the Tanzania Bureau of Standards (TBS), East African Breweries Ltd, National Steel Company, National Institute for Medical Research (NIMR), and State Mining Corporation (STAMICO).
The now-retired civil servant is also chief executive officer of the US-funded Millennium Challenge Account (MCA) Tanzania.
Since assuming the presidency in November last year, President Magufuli has sought to shake up the management of TRA as part of his goal to end tax evasion, boost government revenue collection, and thus raise money for national development projections.
He started by firing the then TRA commissioner general, Rished Bade, just three weeks after his inauguration (almost a year ago to the day), and appointing former Planning Commission executive director Philip Mpango as acting TRA chief.
In December 2015, the president picked Alphayo Kidata, a former permanent secretary in the Ministry of Land and Human Settlements Development, to fill the same post after naming Mpango as minister for finance and planning.
Magufuli also in the same month sacked TRA deputy commissioner general Lusekelo Mwaseba and replaced him with former permanent secretary in the Ministry of Energy and Minerals, Eliakim Maswi.
Maswi was then removed from his TRA post in January this year, after what was officially described as conclusion of his one-month ‘special assignment’. He has since held the position of Manyara regional administrative secretary.
Kidata was meanwhile confirmed as TRA commissioner general in March.
According to the Tanzania Revenue Authority Act of 1995, the TRA board of directors is the "governing body of the authority."
The board is headed by a chairman appointed by the president on the finance minister’s recommendation. The permanent secretaries of the finance ministries in both the Union and Zanzibar governments; governor of the Bank of Tanzania (BoT); and the authority’s commissioner-general all sit on the board as ordinary members by virtue of their positions.
Four other board members are appointed by the finance minister and must have professional knowledge and experience in finance, commerce, economics or law from financial, commercial, legal or economic institutions.
The board is a statutory organ responsible for the formulation and implementation of TRA policy.
It has powers to "give lawful instructions and orders in a prescribed legal notice to the commissioner general in connection with the management, performance and operational policies of the operating departments," says the TRA Act.
But it has no powers to intervene in the determination of tax liabilities of particular taxpayers.
The board also determines, subject to the approval of the finance minister, the terms and conditions of service, salaries and other allowances for the TRA commissioner general, commissioners, officers and other staff of the authority.
Under Magufuli's government, TRA is reported to have boosted monthly revenue collection from an average of 800 billion/- to 1.2 trillion/-. The president's stated goal is to double revenue collection to close to 2 trillion/- per month.
“Reforms of the tax system are vital for the country to secure the funds it needs to finance its economic and social development for the benefit of all its citizens,” Jacques Morisset, World Bank Group lead economist for Tanzania, said in a report last year.