How do I verify authenticity of 25W Apple adapter for iPhone 16 Pro

you can't really

even if the serial number is a valid one it does not mean it's not a fake device with a valid serial number

only way you can be sure is if it's purchased in an apple store or official apple reseller

but if you look on apples online store then they do not sell 25Watt chargers at all

Charging Essentials - iPhone Accessories - Apple

As Rudegar has already mentioned, Apple does not sell a 25W power adapter. This is most likely a fake.

Ref: Power adapters for iPhone - Apple Support

Another alternative:

Plug it in and power-up a MacBook.

Then look in the Setting’s System Report

A genuine Apple power adaptor provides a surprising amount of data about itself to the report.

Admittedly, this too could be counterfeited … but I’m not sure that it ever would be.

HOWEVER … I can’t fathom why one with a “thousand-dollar” phone would even consider skimping on a power adaptor — the only thing standing between the low-voltage DC device and high-energy AC voltage.

gmse02..

Perhaps like some other products marked with Apple

and assembled offshore in Asia, those might have a

reasonable assumption in they could've been made

for use with an iPad or other device. ~ Others were!

The tiny 12W power brick versions also had questionable

reception by those who found them in unfamiliar markets.

Of those with USB-C power-out ports, in power adapter

IF you haven't the official USB-C cable, it may have been

made for use with iPad and Power-Delivery specs. With

little info on what are now Obsolete versions exist.

I'd look up the first two letters of the numbers on the box.

Where those might be a marketing area, it could tell more.

[An idea, but that same Number has been Re-Used!!]

I'd not worry about it so much; especially if you use older

iPads, maybe not the Pro models. I'd use that one with an

iPhone, so long as its power output could both 'Charge &

Power' the device/s. Should be fine ~ or, until it's Not!

+1