The Christian charity Stewardship is hosting its annual 40acts challenge, which encourages people to show generosity and do a different act of kindness each day for Lent.
Christians associate Lent with "giving things up", and it's traditionally a period of prayer and fasting for 40 days in preparation of Christ's Resurrection.
The challenge begins today on Ash Wednesday and around 100,000 people are expected to join in.
In 2015, 76,000 people from the UK signed up to take part in activities ranging from cleaning graffiti off local buildings to popping bars of chocolates into someone's bag.
Everyone that signs up will be sent a daily challenge along with a biblical reflection.
Debbie Wright, head of content at Stewardship, said: "40acts began as a simple idea and has captured the imagination Christians and non-Christians.
"We all lead incredibly busy lives and often forget that it is the smallest acts of kindness that can transform a person's day. Intentionally smiling at someone on a crowded train and saying good morning, rather than burying our heads in our devices, unbeknown to us, could make a huge difference.
"The question we pose every year is: 'What if Lent could be about more than simply giving up chocolate? What if it was a preparation for a lifetime of big-heartedness?"
Listen to Premier's Rosie Wright speak to Frances Maude from Stewardship here:
