Changing roles from account management to Scrum Master.

Here are a few pieces of advice:

There are very few entry-level Scrum Master positions, and the market is over saturated with experienced Scrum Masters. I don't want to be discouraging, but you'll need to be persistent and realistic.

• Start with a focus on Scrum rather than Kanban because there are more opportunities with Scrum. Learn Kanban once you get in the role, though.
• Gain practical experience by working as a Developer on a Scrum team that delivers a product before starting as a Scrum Master.  
• Find ways to practice Scrum in a volunteer opportunity or ways to use it in your current position,.
• Sure, a PSM I certification may open doors, but by themselves won't get you a job offer in most cases. Experience trumps certifications every day and twice on Sunday.
• Start thinking about the transferable skills you already possess as an Account manager. Start learning how those strengths show up in Scrum contexts (e.g., facilitating, coaching people, or causing the removal of impediments). What are your gaps?
• Read the Scrum Guide.
• Read "Scrum – A Pocket Guide" 4th edition by Gunther Verheyen. 

• Join Agile communities of practice - many are online and free.

All the best,

Chris

I now work as an account manager for a telecom corporation and am looking to change careers. I was considering applying for a Scrum Master position. 

Given that you're already used to managing stakeholder relationships, is there any reason for not developing your Product Ownership skills first? Perhaps that's the gap which first needs bridging in the telco you work for.

.Professional Scrum Master I (PSM I) is a good starting point for Scrum Master certification, and it is well recognised in the industry.
To land a Scrum Master role, one option is to explore opportunities within your current organisation—there may already be openings or Agile initiatives where you can get involved.

Alternatively, you could consider pursuing the Professional Scrum Product Owner I (PSPO I) certification. As @Ian mentioned, you already have relevant experience in that space through your work as an Account Manager.