64 billion messages passed through WhatsApp in a single day this week, creating a new company record.

The over-the-top messaging provider made the announcement on Twitter in the early hours of Wednesday morning, U.K. time.

Specifically, it said it had handled 20 billion sent messages and 44 billion received messages in a 24-hour period. The latter exceeds the former since people tend to send a single message to multiple sources using WhatsApp.

Obviously there is a degree of double-counting there, but nonetheless, that is a significant number of OTT messages processed.

By comparison, in a report published earlier this year, Deloitte predicted that global SMS volumes will come in at 21 billion per day this year.

WhatsApp, which agreed to be acquired by Facebook for $19 billion earlier this year, is witnessing phenomenal growth. Just three months ago, on New Year's Eve no less, it reported handling 54 billion messages (18 billion sent and 36 billion received). And that was a significant increase on the 18 billion messages (7 billion inbound, 11 billion outbound) it processed on the same date a year earlier.

When WhatsApp CEO Jan Koum announced that the company plans to add a voice service to its offering at Mobile World Congress just over a month ago, he said that his company had 465 million users. With subscriber additions clocking in at 1 million per day at the time, that figure has doubtless increased by some margin now too.

Indeed, Facebook CEO Mark Zuckerberg believes the company is well on track to connect 1 billion people.