Subway is quickly becoming the bitcoin fast-food franchise, albeit unwittingly and unofficially.

A third Subway sandwich shop, following the lead of shops in Moscow and Allentown, Pennslyvania, is now accepting payments from customers bearing bitcoin.

The latest outlet, this time in Bratislava, Slovakia, has accepted bitcoins since 13th November, when the first payment was made to the wallet associated with the shop. Since then, a modest five payments have been made.

With now three Subway shops across the world accepting bitcoin, questions are beginning to be asked about whether it is merely coincidence, or something else.

Subway has over 40,000 stores around the world, so three seemingly unconnected stores in the US, Russia and Slovakia are a drop in the ocean of the wider Subway business.

At the same time, there have been no reports of McDonald's or KFC accepting bitcoins. Subway the brand is beginning to become associated with bitcoin ­­– at least for reddit’s bitcoin audience.

On 3rd November, a tweet revealed the first Subway shop accepting bitcoin in Moscow:

However, an earlier picture posted on Instagram indicated that the shop had been accepting bitcoin since the summer:

Days later, on 8th November, it emerged that a Subway in the United States was also accepting bitcoin. Though there was initial scepticism, a follow-up video confirmed that the outlet accepted bitcoin; on the flip side, the video also confirmed that payments with bitcoin can be tricky and slow if both parties aren’t entirely clued up.

News of the shop in Bratislava first emerged on reddit in a post by user jangwao, who said that the owner of the franchise, Martin Petrus (according to this local report), had previously used bitcoins on an online business.

It isn’t clear as to whether the three shops independently decided to accept bitcoin payments, or if the Moscow outlet inspired the franchise owners in Allentown and now Bratislava.

However, the first payments to the wallet addresses associated with the Allentown and Bratislava outlets are both later than the reports of the Moscow outlet, so it is possible that this is a case of bitcoin-savvy business owners being persuaded by the example set by others.

According to posts on a local Slovakian forum, the Subway franchise is using MyCelium to process bitcoin payments [Google Translate], just like the shop in Moscow. Update 19/11/2013 17:08 – the store actually uses btcpos.com.

A spokesperson for Subway wouldn’t be drawn on whether the brand approved or disapproved of their franchisees using bitcoin and noted that all Subway stores are “independently owned and operated”.

However, they added: “As part of their franchise agreement, franchisees are required to comply with all local laws.”

Update 19/11/2013 15:13 – Bratislavia Subway owner Martin Petrus, also the founder of a Slovakian bitcoin exchange that launched in August of this year, has been in touch via email and says he only found out about the Allentown and Moscow subways after he started accepting bitcoin in his shop.