The public body handled over 600 collective conciliations in 2022-23, compared to 500 the year before.
There were 649,000 calls to the helpline and 105,000 early conciliation notifications, in which Acas speaks to the employer and employee separately to try and resolve a dispute.
It’s new website advice for employers and employees on conflict resolution also received 14.4 million visits.
More on conflict:
Susan Clews, Acas chief executive, said resolving disputes outside of court saves employers and employees time and money.
She said: “We also helped over 72,000 individual dispute cases avoid the need to progress to a costly tribunal.
“With the cost of workplace conflict in Britain estimated to be £28.5bn per year, our services continue to be a critical national asset.”
More than one in three workers experience conflict at work, an average of around £1,000 for every UK worker, according to research from employment expert group ReWAGE.
Richard Saundry, author of the ReWAGE report, said the pandemic exacerbated workplace conflict.
Speaking to HR magazine, he said: “Conflicts were arguably put to one side during this time and have now resurfaced.
“Also, if you add into the mix, the growth of remote working, impacts on mental health and wellbeing and problems of staff retention, the environment is one in which conflicts between staff, managers and organisation can escalate.”
Chris Warhurst, director of the Warwick Institute for Employment Research, said economic pressures are also a factor.
Speaking to HR magazine, he said: “With tight labour markets, falls in standards of living and a weak economy, there are challenges for both employers and employees but, for the same reasons, pressures on both to resolve any tensions.”
Saundry said early conflict resolution saves the emotional and financial pressures of a tribunal, or the employee’s resignation.
He added: “Litigation involves lost management time, legal costs and potential compensation, as well as significant stress and pressure for those involved.
“However, the threat of litigation is often exaggerated and the most significant costs of conflict are associated with resignation, absence and dismissal. So, the best way to avoid litigation is to resolve issues inside the workplace.”
Anna Shields, Director at mediation specialists Consensio, said there are many ways employers can try and catch disputes early.
Speaking to HR magazine, she said: "Firstly, everyone in the organisation needs a base level of awareness of conflict and some core resolution skills.
"Early resolution support services - ranging from manager and HR support, to conflict coaching and workplace mediation - can not only help resolve disputes but also mean employers have the opportunity to help employees earlier.
"Finally, and perhaps most importantly, is for employers to take a strategic approach to conflict, moving from a reactive to a proactive approach.
"This is where HR professionals have the opportunity to lead and reap the many rewards of constructive conflict, such as increased collaboration, innovation and an enhanced employee experience."