Residents of Neath Port Talbot have been urged not to leave donations outside clothing banks and charity shops that have closed during the coronavirus outbreak.
The county borough council said leaving items outside or alongside collection banks, which are closed due to the lockdown, is fly tipping.
It comes as many people have been using the additional spare time brought by the lockdown to clear out unwanted items from their homes.
Neath Port Talbot Council said while it is important to encourage recycling, it needs people to keep these items in their homes until normal services resume.
Council Deputy Leader and Cabinet Member for Streetscene and Engineering, Cllr Ted Latham, said: “We understand many residents are taking this time of movement restrictions to tidy their sheds, garages and attics etc.
"However you still need to ensure any waste is disposed of legally. Where possible our advice is that you retain this waste until things return to normal."
The council said although Household Waste Recycling Centres are closed, regular recycling and waste collection services are continuing to operate.
It added: "If people have waste material that is not suitable for kerbside collection, they must store it on their property until alternative disposal arrangements can be made."
The Wales Council for Voluntary Action has warned many charities in Wales will close their doors for good because of coronavirus.
The closure of charity shops, the cancellation of fundraisers and the increase in demand for charity support services have put extra pressure on both large and small charities in Wales.