I believe that in your case you can use the concept of Nested Resources.
Basically in his routes.rb you will do something like:
resources :blogs do 
  resources :posts
end
This will create routes like:
blog_posts GET    /blogs/:blog_id/posts(.:format)          posts#index
                        POST   /blogs/:blog_id/posts(.:format)          posts#create
 new_blog_post GET    /blogs/:blog_id/posts/new(.:format)      posts#new
edit_blog_post GET    /blogs/:blog_id/posts/:id/edit(.:format) posts#edit
     blog_post GET    /blogs/:blog_id/posts/:id(.:format)      posts#show
                        PATCH  /blogs/:blog_id/posts/:id(.:format)      posts#update
                        PUT    /blogs/:blog_id/posts/:id(.:format)      posts#update
                        DELETE /blogs/:blog_id/posts/:id(.:format)
So you’ll always have the blog ID as a reference in your accounts. 
Heed Note that the helpers of urls will also change, post_path for blog_post_path for example always passing the blog reference as blog_post_path(@blog).