Advertising Mail is due to go live as part of Royal Mail's revised pricing structure next week, when it will offer a substantial discount to the double-digit price hikes approved by Postcomm.
However, direct mail printers were still in the dark on the question of third-party inserts until late yesterday when Royal Mail issued a statement to the members of the Strategic Mailing Partnership (SMP) clarifying the issue.
One DM printer told PrintWeek that there had been conflicting advice from Royal Mail on whether or not customer mailings containing third-party inserts would or would not qualify.
"It's been an absolute farce," he said. "We've been hearing one thing from Royal Mail and then a client comes and says that they've been told the opposite.
"We are the people who should be telling our clients how Advertising Mail will work and to be honest this has left us looking a little incompetent."
Royal Mail has since confirmed in an email to SMP members that third-party inserts will qualify for the Advertising Mail service.
The email, from a member of staff at Royal Mail, said: "Many of you have recently queried whether customer magazines containing third-party advertising qualify for Advertising Mail.
"I have had confirmation from our head of business that customer magazines containing third-party advertising, that are not paid for by the end recipient and that form part of a company's marketing communications do qualify for Advertising Mail."
Lance Hill, group sales and marketing director at 4DM, praised the decision, saying: "While there has been confusion in some parts over the Advertising Mail rules and regulations, it's certainly a positive product to offset the increases that are coming in on Monday and it's certainly good news that third-party inserts are allowed and do comply with the rules.
"In terms of other areas of the marketplace, certainly with the transactional mailers, there is a concern that they haven't got a product that is equally competitive, but Royal Mail has said that they will look into that."
Transactional mail, which makes up more than 60% of the UK mail market, does not qualify for the Advertising Mail because the service only applies to mailings that comprise 100% advertising content and specifically excludes insurance renewals, bills and statements.