A TWEED charity is bursting at the seams with donations after Christmas, but most will never make it on to the shelves.

St Vincent de Paul Tweed president Jan Parker said about 50% of items left at the charity were "unsaleable". "We do appreciate all donations, but some people are dumping their rubbish at our bins," Ms Parker said.

"At all our stores we do our own sorting and that requires a lot of work."

There was a huge amount of donations coming in at the Tweed Heads and Tweed Heads South stores and the disposal cost of items that could not be sold was "extremely expensive". "The biggest problem is furniture. We do not sell furniture anymore," she said.

"Some items left at our store are used to vandalise our building."

St Vincent de Paul Society community and corporate relations manager Julie McDonald said last year, the society spent more than $1.5m managing damaged clothing and furniture.

"We can't express enough gratitude for all of the wonderful donations we receive from the public which help us fund our work in the community." Ms McDonald said.

"However, we find at times like Christmas we get materials we can't sell dumped at our centres.

"We just ask people to think about their donation and make sure the Vinnies store is open. If not, it's likely their donation will be taken or ruined by rain."