Apple Watch Series 5 and business phone

Dual SIM iPhone instructions

https://support.apple.com/en-us/HT209044

Dual SIM Apple Watch instructions

https://support.apple.com/en-us/HT209043

Basically starting with the iPhone XS and newer dual SIM support was added.

• XS
• XS MAX
• XR
• 11
• 11 Pro
• 11 Pro MAX

NOTE: You will then have to pay for a full cellular plan, and your carrier that supports the Apple Watch MUST ALSO support eSIMs.

OR your company's carrier must support eSIM, and your personal carrier just needs to support the Apple Watch

iPhone Cellular Carriers that support the Apple Watch, which models, the radio frequencies each model uses, and the country where they offer service:

https://www.apple.com/watch/cellular

You will have to check with the carrier to see if they support the iPhone eSIM.

Having an iPhone with eSIM is not necessary to pair an Watch.

The GPS + Cellular Watch has an eSIM and can be paired with an iPhone 6s or newer model.

Note: Cellular Watch share the same phone number as the iPhone (so it must be supported by the same iPhone carrier)

You can use Watch GPS + Cellular as a GPS only Watch without activating the cellular radio.

For that, you need to have your iPhone nearby to get messages, calls, ....

The Apple Watch shares the iPhone’s phone number. This requires the iPhone cellular carrier to support the Apple Watch. For this service the iPhone carrier charges a fee. In the U.S. the fee is $10 per month.

I do not think the iPhone 7 has an eSIM, so you would have to add the Apple Watch to your business plan.

It is his company phone and the company pays the bill. He is apparently not authorized to add extra changes to the bill to add the Apple Watch.

Hence getting a newer company phone that has dual SIM support, and he can pay for the 2nd line.

Personally I would just go for a GPS only and keep my iPhone with me.

BobHarris wrote:

....

Personally I would just go for a GPS only and keep my iPhone with me.

That's what I was suggesting.