Storytel generally keeps its planned launches secret until they happen (Mexico and the imminent launches in Brazil and Singapore the exceptions) and so far Jonas Tellander has made no comment on a pending Bulgaria launch, despite TNPS reporting on the likelihood back at the start of 2018.

Storytel has 300,000 Swedish subscribers, a further 250,000 beyond and is aiming for thirty countries

As I reported in January,  in late 2017 Storytel made acquisitions in Iceland, Bulgaria and Turkey (just prior to the launch of TNPS, so not covered here previously).
These were

  • D&D Factory, Bulgaria, the operation behind the Bulgarian audiobook service Audioknigi
  • Seslenenkitap, an audiobook company in Turkey
  • Skynjun, the Icelandic audio-book publisher and internet retailer Skynjun

all leading audiobook operators in their countries.
Since then Skymjun morphed into Storytel Iceland –

Storytel launches in Iceland. Italy, Bulgaria and Turkey next?

Seslenenkitap morphed into Storytel Turkey –

Storytel now live in Turkey. Italy launch imminent and Bulgaria launch soon

and yes, the Italy launch mentioned in those headlines also happened –

Storytel launches in Italy

So will Bulgaria be next?
A visit to the Storytel Bulgaria website offers a boilerplate statement that Storytel Bulgaria is not yet live, and invites consumers to sign up for notification when it happens.
Bulgaria has been on the Storytel international placeholder site since forever, alongside less likely contenders such as USA, UK and China, so that in itself tells us little, but there are other indications, alongside the D&D Factory acquisition, that Storytel’s Bulgaria plans are well-advanced.
From Nordic literary agents who shall remain unnamed I know Storytel has been buying Bulgarian audio rights to successful titles, and of course as the new owners of D&D Factory Storytel has plenty of Bulgarian original audio content in hand.
But this week comes a note on the Sofia Literary Festival site that one of the sessions on the festival programme is titled,

Discussion: Do you love exciting stories? How Storytel and audiobooks can enrich your everyday life.

The festival itself is being sponsored by Storytel, and together this would suggest the Storytel Bulgaria launch is imminent,.
While this may just be advance promotion for a launch in the New Year (which would add spice to the Q4 financial statement in January), what better place to announced the launch than in the Bulgarian capital at the Sofia Literary Festival (11-16 December), running in tandem with the Sofia International Book Fair (50,000 visitors expected) and just in time for Christmas?
Earlier this month Storytel launched in its 14th market, Mexico –

Storytel launches in 14th market – Mexico – with 2,400 Spanish titles accessible across Latin America

and has confirmed it will be launching in early 2019 in Brazil –

Storytel confirms Brazil launch for 2019 as Mexico launch nears

and Singapore.

Storytel to launch in Singapore in 2019

Currently Storytel is operational in Sweden, Norway, Denmark, Finland, Iceland, Netherlands, Poland, Russia, Spain, India, United Arab Emirates, Turkey, Italy and Mexico.
The Bulgaria, Brazil and Singapore launches will take Storytel’s international reach to 17 markets, in only two of which – India and Italy – it will face direct competition from Amazon’s Audible..