Under the Flexible Working Act, all employees who have worked for their employer for 26 weeks or more currently have the right to ask if they can work flexibly.
Due to a change in law, this right now applies from the first day of employment.
Acas will produce a new statutory Code of Practice on handling requests for flexible working to support employers and employees through this change and other reforms, which will be introduced next year.
Acas chief executive, Susan Clews, said the rise of flexible working since the pandemic will improve the lives of employees.
She said: “There has been a substantial shift in flexible working globally, which has allowed more people to better balance their working lives and employers have also benefited from being an attractive place to work.
“It is important for bosses and staff to be prepared for new changes to the law around the right to request flexible working, which will be coming into force next year."
Read more: If we aren't tracking flexible working… what's the point?
This follows research which found half (49%) of UK workers would consider asking for flexible working on day one of a new job, according to research from flexible working social enterprise, Timewise.
Emma Stewart, co-founder of Timewise, said employers need to be proactive in preparing for the influx of requests.
Speaking to HR magazine, she said: “We know a wave of requests are coming when this legislation goes through, and HR needs to think carefully about their response and decide their policies now.
“Otherwise, the unintended consequence is that staff who are more informed and know about the bill will end up with different options available to those who aren’t, which could lead to tension and inequality down the line.”
Next year, Acas will produce a new statutory Code of Practice on handling requests for flexible working to support employers and employees through this change and other reforms.
“Acas has just consulted on a new draft Code of Practice, which strengthens good practice on flexible working and addresses important upcoming changes to the law. The final new Code will be published next year.”
This follows a consultation they held on who should be allowed to accompany an employee at meetings to discuss a flexible working request, the need for transparency about reasons for rejecting a request and making it clear that employers should proactively offer an appeal where a request has been rejected.