Income from tourist accommodation decreased by 2.3% in July 2018 compared with July the previous year, figures released by Statistics South Africa on Monday showed.
The data comes on the back of weak economic growth and living costs, which hampered consumers' spending patterns.
Various types of accommodation establishments recorded a slump in income, from guesthouses and hotels to caravan parks.
"Income from accommodation decreased by 0.5% year-on-year in July 2018, the result of a 4.2% decrease in the number of stay unit nights sold," said Stats SA.
Consumers have in recent months been hit by higher fuel prices, which made travel more expensive.
This was exacerbated by the VAT increase, from 14% to 15% in April.
The tourism industry is a key driver of economic growth, contributing significantly to GDP, with domestic tourism increasingly being viewed as an important source of income.
The recession seen in the second quarter of the year is likely to negatively impact spending, with more fuel hikes expected during the course of the year.
* Sign up to Fin24's top news in your inbox: SUBSCRIBE TO FIN24 NEWSLETTER