Photo app Instagram is ready to get involved in online shopping by letting retailers tag items in their photos from next week, which users can then click through to purchase.

The change will start as a trial in the US and involve a group of 20 retailers including Jack Threads and Kate Spade.

"Mobile has changed the way people shop," Instagram said in a blog post announcing the new feature.

"You browse products while waiting to be seated for dinner, make purchases on your commute into work, and compare prices online when you're at a store to see what's the better deal."

Companies can tag as many as five products in each photo. Browsers can then click an icon at the bottom of the image to purchase it.

It is not certain yet whether the change will be introduced in the UK.

In September, Instagram's parent company Facebook began allowing users to buy and sell to either other through a "marketplace" area on the app.