Belize

Belize has two operators: GSM users don't have a real choice as the only GSM-based operator in the country is DigiCell. 2G EDGE is on 1900 MHz and 3G HSPA which is still marketed as "4G" is on 850 MHz. CDMA-users from US or Canadian networks can activate their device on Smart of if you have a "world phone" with a SIM slot on DigiCell as well.
 * DigiCell (by BTL) - GSM
 * Smart - CDMA-only

Belize used to be one of the few countries that blocked all VoIP like Skype until recently. After a long discussion in 2013 all VoIP was unblocked and is today usable like in the rest of America.

In 2013 Belize's government introduced a mandatory registration scheme for mobile users. All unregistered lines were discontinued. So expect to show an ID while purchasing a SIM card. This is now only possible with authorized dealers.

DigiCell (by BTL)
by Belize Telemedia Limited (BTL), the leading state-owned telco in the country that was re-netionalised in 2009. Actually, if you are on GSM, you don't have another choice in this country

"4G"
It heavily markets its HSPA+ as "4G": "Our DigiCell4G network is referring to an “HSPA+” network that can offer blazing mobile speeds of up to 21 Mbps." This is now called 3G in the rest of the world. "''The network is an enhanced version of a wireless high-speed network and has been classified as an IMT-Advanced or “4G” by the International Telecommunications Union (ITU)." ''This has been a huge marketing problem for the networks, when they will adopt real 4G in the form of LTE eventually. But for now, there is no LTE in Belize.

Availability
SIM Card Activation DigiCell PrePaid SIM Pack (includes SIM card, phone number and $10 PrePaid Card)

These are available at any BTL Customer Services Center, authorized dealers and agents countrywide. https://www.digicell.bz/gsm-site-location/item/10033.html

The SIM pack includes an activated DigiCell PrePaid SIM, an information booklet and a $10 DigiCell PrePaid card.

Insert your SIM into your phone, turn it on and DigiCell will appear on your screen. Load the value from your FREE $10 card onto your account and then you’re all set! You can make and receive calls immediately!

Top-up online https://www.mydigicell.bz/index.php/account/login or agents: https://www.digicell.bz/topup-agent.html

APN: digicellbroadband