Apple now allows users in Taiwan and Switzerland to pay for apps through their phone bills

Apple is quietly adding more modes of payment for iTunes, to cater to users who don't have or don't want to add a credit card to their accounts.

On Tuesday, it started allowing users in Taiwan and Switzerland to pay for their apps, books and music through their phone carrier. (In Taiwan, that excludes books because Apple doesn't sell its eBooks there.)

So far, only Far EasTone users in Taiwan will get the option. Apple hasn't announced which telco it's tied up with in Switzerland, but it's likely to be Swisscom, which has previously launched carrier billing with Apple competitors Google and Windows.

This move adds the two countries to Germany and Russia, making Apple's total four globally. Taiwan is the first in Asia to get this mode of payment.

Apple started carrier billing in Germany in October last year, working with O2/Telefonica there, before expanding to Russia in December.

Users who have the option can go to their account settings and select to pay via their monthly mobile phone bills.

Although credit and debit card penetration has been rising in Asia, where its emerging markets have for years lagged behind in adoption, more phone makers have been striking deals to allow phone billing, in a bid to remove friction around paying for apps.

Google allows carrier billing in huge countries in the region such as Indonesia and India, and Android users in Singapore have been able to pay this way since 2013.

Google said in May this year that the number of people who have bought apps or made in-app purchases has quadrupled in the year since it launched phone billing in March 2015.

It also noted that nearly a third of Indians own a smartphone, but less than 3 percent of the population uses credit cards.

We've reached out to Apple for more.

UPDATE: Aug. 16, 2016, 1:52 p.m. SGT An earlier version of this story only noted Taiwan got the roll out. The story has been updated to include Switzerland.