UnitingCare retail operations manager Richard Peoples said the problem tended to spike at this time of year, when many people had more time to clean out their homes.

Compounding the issue was that some people also used op shops to dump rubbish, he said, rather than taking it to the tip.

Mr Peoples said the three UnitingCare op shops in Bendigo would spend between $25,000 and $30,000 a year on tip fees to get rid of rubbish and other unusable items, money that could be put to better use by the organisation.

He estimates the amount of rubbish that is left outside its stores at this time of year is triple that of a typical week.

Clothing and other items being left outside op shops is an issue that is familiar to St Vincent de Paul Society Victoria.

Chief executive officer Sue Cattermole asked people to give donations during shop opening hours and ensure items were in “reasonable condition for subsequent use”.

“Charities like Vinnies often spend considerable time and money disposing of donated goods that can no longer be used, so it’s important to be discerning about what makes a suitable, quality donation,” Ms Cattermole said.

RSPCA Victoria op shops co-ordinator Delaney Watts also urged the community to make sure their donations counted by taking them in during store opening hours, rather than leaving them outside where they could become damaged or soiled.

Mr Peoples said theft was another problem that arose when people left donations outside, with some taking the opportunity to pilfer items in good condition.

People have also been encouraged to be mindful of what items can be accepted by op shops.

Ms Cattermole said Vinnies op shops were also unable to accept baby items that did not conform to Australian Safety Standards, broken appliances or electrical items with a heating element.

Mr Peoples said there were certain items, such as bicycle helmets, that op shops were unable to receive because they could not ensure they were safe for resale.

For those unsure that what they have is good enough for donation, he has a suggestion.

“If it’s not something you’d give to your best friend, it’s probably not something we can use,” Mr Peoples said.

Despite the recurring issues, the charities said they were grateful for any assistance they received and thanked all those who had contributed to their causes by donating items.

Following is a list of items, provided by Vinnies, that are examples of what is suitable for donation: