Slack revealed a net loss of $138.9m for the year ending January 31, 2019, as it filed papers for its IPO late last week.
The company, which has transformed the way many businesses and organizations communicate through its eponymous messaging app, announced revenue of $400.55m in an S-1 registration form posted with the Securities and Exchange Commission on April 26.
The company revealed cash equivalents as of January 31 of $841m as it continues it bid for a direct listing on the New York Stock Exchange (NYSE) under the symbol SK.
Slack's user base, as of January 31, is comprised of more than 10 million daily active users (DAUs), with paid customer numbers up 49% year-over-year compared with fiscal 2018 to 88,000.
The filing revealed that the number of customers paying more than $100,000 based on annual recurring revenue (ARR) stood at 575, representing an increase of 93% year-over-year compared with fiscal 2018.
In its S-1 registration form, Slack said: "We believe our market remains underpenetrated and we will continue to expand our marketing and sales efforts to reach more users and organizations and to increase the number of paid customers.
"We plan to continue to grow use and users within organizations on Slack by increasing our investments in our direct sales force, customer success and customer experience teams, along with new user education initiatives."
Slack's losses can to some extent be attributed to its large spend during its fiscal year 2019, during which it spent more than half its revenue on sales and marketing, with the company reporting $233m in operating expenses on the segment.
Slack warned that expenditure would likely increase as it looks to establish systems to ensure it meets compliance and regulations as a raft of new data laws come into force in many of the markets in which it operates. The warning followed the example set by the EU's General Data Protection Regulation (GDPR) which came into force in May 2018. The company also noted that it would continue to invest in ensuring performance capabilities.
"We may incur substantial expense in complying with the new obligations to be imposed by the GDPR, and we may be required to make significant changes in our business operations and product development, all of which may adversely affect our revenues and our business overall," said Slack.
"Our continued growth depends, in part, on the ability of existing and potential organizations on Slack to access Slack 24 hours a day, seven days a week, without interruption or degradation of performance.
"We have in the past and may in the future experience disruptions, data loss, outages and other performance problems with our infrastructure due to a variety of factors, including infrastructure changes, introductions of new functionality, human or software errors, capacity constraints, denial-of-service attacks, ransomware attacks or other security-related incidents," the company added.