Which paid for account fits our need? (external client access)

[Gemma Walsh Woodcock]

We run a series of projects for different clients.

We are a small team of 2 people and we are looking at paid options for trello. I don't know which level meets our need.

Our need: We need to have a board/client project. This could be 10 different boards/projects total. The client needs to be able to access their own board so they can see the progress of their project.

We currently use basecamp and we can have unlimited client access access to the projest meaning we don't need to pay for client access.

However I don't like basecamps boards as much as I like trellos so I want to explore moving across.

Do we have to pay for the clients to access the boards in Trello or is there an option for the clients to access the boards without paying for them like in basecamp? 

[Rasmus Wulff Jensen]

I've made this 10 min video on how the new rules work via various examples: https://youtu.be/rqmCHU_QxY8 (Your scenario is similar to Example 2: https://www.youtube.com/watch?v=rqmCHU_QxY8&t=387s)