1. No.
2. You could buy a phone without a SIM. And yes you could use any SIM. Sometimes Apple blocks non EU SIM. If.so you have to use a SIM (pre paid is ok) for init the Phone for a few weeks. After that you could use the iPhone with any sim.
3. Yes (for the SIM) the Phone is a credit and ends if the phone is payed to 100%.
   For SIM you could use http://info.o2online.de/kuendigung/

For a phone without a contract use https://www.o2online.de/e-shop/handys-ohne-vertrag?ohne-tarif=ja

or toggle the switch in the upper  right corner to right position as shown in the pic.

Hallo ​@Rajegowda,

welcome to our o2 Community 

This is great help from schluej, could you buy an  iPhone 16 Pro without a contract?

The instalment plan can be paid at once after the first installment or any time you want, for this to order you need to register the instalment plan later with the Vertragsnummer, the contract number which you will get by mail from us about 2 weeks after the iPhone arrived.

But otherwise the installment plan will end automatically and with  us it does not need to be cancelled.

Best Regards,

Gerrit 

When I visit the shop, they say it's not possible to buy an iPhone 16 Pro without a tariff. If I choose to buy it with a contract, I must also purchase a SIM card. Is it the same as needing to buy an O2 SIM to get the phone on contract?

​@Rajegowda The shop is a franchise, so the have no interest to sell only a phone. 

If you buy the phone online (see link above) you could get the phone (if offered) without a contract.

If I choose to buy it with a contract, I must also purchase a SIM card.

I don’t understand this question…

If you would buy a phone in a O2 shop:

1. You get a Phone without installment plan. Most you pay the phone in 12 or 24 Months. And your are able to Ende the installment with paying with paying the rest of the open amount.
2. You get a Mobile contract of cause with a (e)SIM with a runtime of 24 Months. After the 24 Months the contract will auto renew for 1 month until you cancel the contract. It is not possible to Ende this contract bevor the 24 Months ends!

And if O2 reject the installment option for the phone than you will have, for U, a useless mobile contract.

So please buy the phone online with the link, without a mobile contract!
If your company SIM is from a German provider you will not need a SIM.

Only if you company SIM is not from EU it could be that you need a German SIM.

Than please buy a PREPAID SIM (use the most inexpensive prepaid sim e.g. ALDI).

For 24 installments you will pay 58,50€ / month for 256GB Version.

Are you able to order a phone online?

Hello ​@Rajegowda,

could try schluejs link and find an iPhone 16 pro to buy on our website without a mobile contract attached?

Best Regards,

Gerrit

Thank you so much I just ordered it .

Waiting for my iphone now 

That is great, ​@Rajegowda, that schluej could help you to order an iPhone 16 Pro and a new smartphone only 

Once you have received it, tell us how you like it if you want to 

Best Regards,

Gerrit

For all readers, comment moved to ordered not delivered | O₂ Community