I have had this phone since the day they came out in March 2016. Adore it. It is unlocked. I have ATT pay as you go service. Thought since it is unlocked I can just buy a SIM card anywhere in the world and it would work but now see that my model may not work in Europe. Did not even know there were different "models"!!! it is printed in tiny letters/numbers in the back of the phone, Anyone have experience with this phone?
According to Apple the A1662 has
LTE (Bands 1, 2, 3, 4, 5, 8, 12, 13, 17, 18, 19, 20, 25, 26, 29)
CDMA EV‑DO Rev. A (800, 1700/2100, 1900, 2100 MHz)
UMTS/HSPA+/DC‑HSDPA (850, 900, 1700/2100, 1900, 2100 MHz)
GSM/EDGE (850, 900, 1800, 1900 MHz)
In particular, note that the A1662 iPhone SE model -- sold in the United States for AT&T, T-Mobile, and Verizon -- supports LTE bands 13 and 29, but not 7, 28, or the TD-LTE range (38, 39, 40, and 41) or TD-SCDMA.
Europe is a big place comprised of dozens of countries. Where did you intend to use it?
From what Nigel has posted, sounds like it will work as at least a 3G phone all over Europe. In my experience, that's actually good enough. My Android phone has only LTE 7 for Europe, and when I was in Portugal this year, I occasionally picked up LTE 7 but often just 3G/UMTS. And it was more than adequate for maps, email, etc. (2G/Edge on the other hand is almost unusable these days.)
Will be in France, Netherlands and Belgium.
Last April we went to Netherlands and Belgium with a much older phone.
My carrier is Verizon. They set us up with a plan to meet our needs and it worked very well.
Consider contacting your carrier. They will be more than happy to help you.
I have a pre paid phone with ATT. They cannot help me. It's unlocked, so I need to find a plan there that will work,
I can recommend the Dutch Vodafone SIM. I see you are headed to the Netherlands anyway - but if you won't get there first, you can buy a Dutch Vodafone SIM on eBay. Search for "vodafone you sim." Seller was "cheapeusims" when bought mine, still is I think. About $8.50 USD shipped to US. You can set up an account at home in the US and add funds to it ahead of time - but don't add them too soon before you leave for Europe (funds expire in six months). You add funds and then buy a "bundle" for a month using the funds you've added. Be sure not to activate a bundle until you are ready to use it - expires 30 days after you buy it (but you can add the funds before that).
You can use this SIM in all three countries and within the EU. You can get 2GB of data for 10 euros (the SIM you buy comes with no credit on it) or 6GB for 20 euros - good for 30 days.
This is otherwise still valid from last year: