UPDATE:

The programme was set up in collaboration with Tay Paper which has now declared bankruptcy. Given this development, we are unsure of the reliability of these bins or even if they will continue operation. 

…

Recycle used red packets at DBS/POSB branches all year round! Bins are located outside all branches and will be accessible during mall operating hours or banking hours. Click the link for participating branches.

“With the amount of ink and gold stamping involved, red packets are not easy to recycle and often end up incinerated. To solve this problem, DBS partnered Tay Paper Recycling in 2019 to launch a dedicated red packet recycling initiative. You can recycle your red packets, DBS QR Gift cards and even Mandarin orange carriers.”