(Yicai Global) Sept. 30 -- Apple’s iPhone 13 series is becoming the lineup with the longest waiting time, with analysts saying the three- to five-week delivery period is due to supply chain constraints and robust demand.

The US tech giant has not yet commented on the long waiting time, nor has it given any explanation. But according to analysts, the reasons behind the delay are tight supply and high demand for the newest iPhone 13 and iPhone 13 Pro.

A consumer in Shanghai preordered an iPhone 13 Pro Max on Apple’s website on Sept. 28, and is expected to receive it only at the end of next month, the person told Yicai Global.

“While admittedly part of the expansion in the lead times is on account of the supply chain constraints, we still find the material increase in the lead time in Week 2 relative to Week 1 as an indicator of the robust demand for upgrades, likely exceeding low investor expectations into the launch,” Samik Chatterjee, an analyst at J.P. Morgan Chase, said in a recent research report.

In Apple’s earnings reports for the past two quarters, Chief Executive Tim Cook warned investors that the global chip shortage could cut sales by between USD3 billion and USD4 billion. He also noted that the huge demand for chips has exceeded the company's expectations.

Still, institutional concerns about the supply chain are fading. TF International forecast iPhone 13 shipments to rise about 10 percent this year compared with iPhone 12 shipments last year. The Hong Kong-based investment management services provider, however, also identified short supply as a possible drag on shipments in the fourth quarter.

So far there have been no reports of constrains in Apple's supply chain, consultancy firm Omdia’s semiconductor analyst Li Zegang told Yicai Global, adding that the supply of fifth-generation networking chips is not tight and also because suppliers prioritize Apple.

Several suppliers of Apple and US automaker Tesla said on Sept. 26 that they would halt production in Chinese factories for several days to comply with stricter energy consumption policies. But analysts believe that this would only have a limited impact on Apple’s supply chain.

Apple's printed circuit board supplier Unimicron reportedly announced it will temporarily close three units in China from Sept. 26 to Sept. 30, noting that it will not affect its production as other factories will be working still.

Taiwan chipmaker United Microelectronics said that the company's plant in Suzhou is operating at full capacity and can produce over 80,000 wafers a month.

Editor: Futura Costaglione