Sony is breaking with its current release schedule for its flagship Z series and will drop its next flagship much later than might've been expected.
A source told TrustedReviews that the Z4 "will not be released until September 2015". That's a year on from its predecessor, the Z3.
Previously, Sony was outing a new Z handset every six months or so. The firm was criticised for this by consumers concerned their new smartphone would be obsolete barely half a year later.
A September launch would mean the handset would most likely debut at tech trade show IFA.
This will be held from September 4th-9th this year. It would also mean the handset could go up against the Samsung Galaxy Note 5 in the battle for market share and mind share.
Samsung has used IFA to launch the latest in its Note series for the past few years.
The Z4 is rumoured to run a Snapdragon 810 processor and Android 5.0 Lollipop. Little else is known about it at the moment.
Sony revealed its latest tablet, the Xperia Z4 Tablet, at Mobile World Congress last week.
It's thinner and faster than its predecessor, and looks a real Android rival to the iPad Air 2.