Comfi is a US-based company, but they have a very international selection of cards. You can find well priced cards with access numbers in most countries worldwide.

Description:Comfi.com is a reseller of prepaid calling cards, and other products, on behalf of several 3rd party telephone companies. They are the top ranked calling card company according to Alexa.com

Carriers represented :ACC, AT&T, ECC, IDT, IDTE, NTC, NW-IP, RNT

Other products & services：Conference calling, VoIP internet calling services, small business PBX services, mobile prepaid plans (for selected mobile carriers)

Service details:US domestic rates
1.3 cents/min with local access or 2.3 cents/min with toll free access. Some cards have even lower rates, but also charge a maintenance fee.

Sample international rates
These are per minute rates for cards with no extra fees: Afghanistan 22￠, Australia 1.8￠, Bulgaria 2.5￠, China 2￠, Colombia 4.5￠, Romania 3.2￠, Ukraine 9.6￠.

Fees
Lower rate cards carry a weekly maintenance and/or connection fee.

Amounts available for initial purchase
$5, $10, $20, $50 and $100.

Recharges
Online.

Lower rate and extra fees VS higher rate and no fees
Some calling cards from Comfi carry a weekly maintenance fee, but charge a lower per minute rate. These are recommended for people who want to use up the card with one or two calls because they will end up talking more despite the extra fee(s).