back of my iphone SE is smashed how much would repair cost???

The bottom line here is that back glass damage to the SE cannot be repaired.

Make an appointment at the Apple Store or take the phone to an authorized Apple service shop to let them go over your options with you under "Other Damage"

You can find a list of authorized shops in your area using this link: Find Locations

Good luck

Neonnyt wrote:

This doesn’t not help my issue the web only repairs 12 up

That's because the back glass can not be repaired on that model. You can find the price under "other damage".

The phone will have to be replaced.

Hello ~ I don’t think the back glass can be replaced on an iPhone SE but the entire iPhone will need replacing. So it would be “Other Damage” and probably $99 if you have Apple Care. So…yes *KiltedTim’s* reply is in fact helpful.

~Katana-San~

Neonnyt wrote:

This doesn’t not help my issue the web only repairs 12 up

Then contact Apple yourself:

Genius Bar Reservation and Apple Support Options - Apple

No one participating here works for Apple. All we can do with this sort of question is refer you to published information.

iPhone Repair & Service - Apple Support

Hello~ No one does. That is why we need to make arrangements such as AppleCare before catastrophic events occur. Nothing can be done except replace the iPhone. Sorry.

~Katana-San~

Hello~ No…I do suggest you sign up for an AppleCare package when you purchase a new iPhone though. Example…it would be like your home burning down and then trying to purchase insurance on it….doesn’t work that way.

~Katana-San~

Then, you will not be repairing the phone.

No. Apple will inspect the phone....before....AppleCare+ goes into effect.