KFC expects disruption to some restaurants to continue for the rest of the week after a new delivery contract with DHL sparked chicken shortages across the country.
More than 500 of the chain's nearly 900 stores are still closed, while many of those that are open are offering limited menus or have cut their hours.
A KFC spokesman said: "We anticipate the number of closures will reduce today and over the coming days as our teams work flat out all hours to clear the backlog.
"Each day more deliveries are being made; however, we expect the disruption to some restaurants to continue over the remainder of the week, meaning some will be closed and others operating with a reduced menu or shortened hours."
KFC said staff on short-term contacts working in restaurants owned by the chain would be paid the average hours worked per day over the past 12 weeks, while those on salaries would be paid as normal.
However, 80% of KFC outlets are run on a franchise basis.
"Franchisees will be seeking their own independent advice, but we're encouraging them to adopt this policy too," said the chain.
The closures left one young fast food fan frustrated, asked if she was disappointed about not being able to get a KFC, she said: "A little. Well, I don't look sad but I really am disappointed. I'm mad at KFC.
"Look at them, they're just chillin', they're happy. Sorry, we're mad with them. We want to get in there, sit down, have some food, but we can't do that today. Sorry, but I'm mad at them."
The closures were the result of delayed chicken deliveries by DHL, which announced in November that it had been appointed alongside QSL to manage the supply and distribution of food products and packaging for more than 850 KFC restaurants throughout the UK.
"Due to operational issues a number of deliveries in recent days have been incomplete or delayed," DHL said in a statement.
"We are working with KFC and our partners to rectify the situation as a priority and apologise for any inconvenience this may have caused."
KFC was previously a client of Bidvest Logistics.