For the entire month of May 2021, McDonalds Singapore is offering free items when you purchase via McDelivery. Do note there is a minimum spending to redeem the free items.
Here are the promo codes for the free items:
McDelivery May 2021 Free Items
What: Various McDonalds Free items
When: Until 31 May 2021
Where: McDelivery Website
Images from McDonalds Singapore
