Eftpos machines were parked at the Perth Royal Show on Monday, leaving cashless punters unable to afford their display bags and dagwood dogs.
The outage saw lines lengthen in the side corridor, with some still in line admitting they waited an hour for services to be restored.
One man told 7NEWS: “I wanted a showbag, they didn’t have eftpos. I want to go home!”
A spokesperson for the Royal Show said they hoped the problem could be resolved before the doors open on Tuesday.
“There was a problem with telecommunications on Monday,” he said.
“The size of the crowd has pushed the telecommunications capacity at Showground,” he said.
“We mitigated the situation by providing hotspots on the floor for operators and suppliers. We are working to fix the problem to return to normal by Tuesday.
The Perth Royal Show is open daily from 10am to 9pm at the Claremont Showground, with the last being October 1st.