Charities have told the BBC of their disappointment at Amazon closing its charity donation scheme by 20 February.
The BBC has spoken to several UK charities about the end of AmazonSmile, a scheme that allows customers to donate to a charity of their choice when purchasing items on Amazon.
The firm said the scheme had not had the impact it had wanted it to.
But charities have said they are sad to see it go, with one saying small charities will suffer the most.
In an email, the online retail giant said AmazonSmile had not "grown to create the impact that we had originally hoped", noting that the average donation to UK charities in 2022 was less than £137.
It said it will donate an amount to participating organisations equivalent to six months of what they earned from AmazonSmile in 2022.
The scheme was launched in 2013, and saw the corporation donating a small percentage of the sale price of items on its website to a charity chosen by the customer.
The decision comes weeks after Amazon announced plans to cut more than 18,000 jobs, the largest number in the firm's history, as it battles to save costs.
James Jackson, RSPCA head of corporate partnerships, said it was "disappointed" by the closure of AmazonSmile, through which it has raised £430,000 since 2017.
"While we're saddened to see AmazonSmile close, we note Amazon's commitment to prioritising other philanthropic projects instead," he said.
Amazon engages with other charitable causes, as well as having a product donation programme, which it says provided more than 15 million essential goods to those in need in 2022.
Vanessa Martin, founder of the Childhood Tumour Trust, criticised Amazon for saying the scheme had not had the impact it hoped for.
"For tiny charities like ours that rely on fundraising to exist, the phrase 'every penny counts' couldn't be truer - particularly in the times we are living in," she said.
The charity she founded aims to help families with children who have been diagnosed with neurofibromatosis, a condition that causes tumours to grow on nerves.
She said it had raised £2,000 through the scheme - enough money to send five children to a therapeutic camp.
"It's still a lot of money," she said. "Their attitude is crazy... when we are happy with a £10 donation, are they saying it's better to not give anything?
"No doubt, it will be the lesser-known [charities] that suffer."
The impact has been felt at charities worldwide, with the Global Sanctuary for Elephants saying it was "upset by this inconsiderate decision", and US-based SquirrelWood Equine Sanctuary saying the donations it had received "meant the world".