WhatsApp is set to make a major change by charging users for the first time.
The changes will affect users of the WhatsApp for Business version of the popular messaging app that are a bit sluggish to replying to messages.
The WhatsApp Business API will allow businesses to respond to messages from users for free over an initial 24 hour period.
However users will then be incur costs for any messages sent after this time, with late messages charged via a fixed rate by country per message.
WhatsApp for Business charges
WhatsApp says that the service can be used in a number of different areas for business customers, such as send shipping confirmations, appointment reminders or event tickets.
Business users could also use the service for speedy customer support replies, and send notifications directly to individual users.
The consumer-facing version of WhatsApp has around 1.5 billion users worldwide, with WhatsApp for Business some way behind with just three million users signed up since its launch in September 2017.
"We will bring more businesses onto WhatsApp over a period of time," WhatsApp said in a blog post announcing the news. "To do so, we will work directly with a few hundred businesses and a select number of companies that specialize in managing customer communications."