It emerged at the Tax Indaba on Monday that the South African Revenue Service (Sars) might not be able to collect about 40% of outstanding money from tax payers‚ which has risen from about R85-billion in 2015 to R143-billion.
It is "questionable" whether Sars would be able to collect this portion of the debt‚ which relates largely to disputes or debt that has been outstanding for more than four years‚ Fabian Murray‚ acting chief officer for business and individual tax at Sars‚ said at the indaba.
Instead‚ Sars would focus on achieving the other 60%‚ said Murray.
"The increased debt book is also an indication of the strain taxpayers are experiencing‚" he said.
This followed a speech by finance minister Nhlanhla Nene‚ who warned that the government was likely to miss its tax collection targets in the context of a recession.
While shortfalls have been attributed to the slowing economy‚ Nene said‚ "We cannot ignore the potential impact of a reduction in the effectiveness of tax administration.
"Tax avoidance and tax evasion will be on the rise in any economy that is growing more slowly and where taxes have been increased."
In recent months‚ the revenue service has pushed to restore its credibility following years of maladministration under suspended commissioner Tom Moyane.