Will an unlocked Iphone Xr work in Nigeria

Wireless carrier support and features for iPhone in Africa - Apple Support

You do not say which exact model you have, where you bought it and with whom it was previously locked. Remember, this is an international forum and for all I know you could be posting from Antarctica. I believe most phones will work in other countries though some features may be missing or lack support. Generally it makes sense to buy the phone in the country where it will be predominantly used.

iPhone XR - Technical Specifications - Apple

Find the right iPhone for the right country or region. - http://www.apple.com/iphone/LTE/

I believe Apple also sells locked phones. Ours was, because it was purchased complete with a carrier plan in an Apple Store. If you are buying one then make sure it is very clear you want an unlocked one.

I believe the country of origin is part of the model number. Somebody asked about a phone her e the other day and included a model number. When I looked it up online it said it was an iPhone from Belgium (and two other countries).

Limnos wrote:

I believe Apple also sells locked phones. Ours was, because it was purchased complete with a carrier plan in an Apple Store. If you are buying one then make sure it is very clear you want an unlocked one.

I believe the country of origin is part of the model number. Somebody asked about a phone her e the other day and included a model number. When I looked it up online it said it was an iPhone from Belgium (and two other countries).

Both correct. The full statement should be "Only Apple sells unlocked phones, but Apple doesn't only sell unlocked phones." 😉

The model number can be by country, but it can be by region also. I think it depends on where the distribution center (or centre) is.

If it is really unlocked (meaning that you bought it directly from Apple, either an Apple store or Apple online) then it will work in Nigeria. Note that Apple is the only dealer in the US that sells unlocked phones. Other stores do not sell unlocked phones, although occasionally you will encounter a salesperson who may not be entirely truthful. As Limnos says, there are model differences, so all functions may not work. If you buy from a carrier in Nigeria you have a much better chance of getting a phone that will work 100%.

It would depend upon the technology Nigeria uses and which model phone you have. If you are thinking about using a phone from another country then there's all kinds of issues you need to note, including lack of warranty support, technology incompatibilities, possible import fees.