Assembly

Assembly vs. Karbon

Updated November, 2025

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While both Assembly and Karbon help accountants manage their clients, Assembly has a superior client portal experience, more flexible file sharing models and automations, and better project management features. If you’re looking for a seamless, branded client experience, Assembly is the better choice.

  • Assembly has a superior branded client portal experience
  • Assembly has task management & collaboration beyond email
  • Assembly has a flexible secure file sharing model
  • Assembly has automation depth with 3rd party integrations

What do customers say?

While Karbon offers more accounting-specific practice management workflows, users rate Assembly's client portal experience higher.

See the full comparison on G2

Capterra score

Assembly
4.8/5
Karbon
4.7/5

Ease of Admin

Assembly
9.4/10
Karbon
8.2/10

Ease of Use

Assembly
9.4/10
Karbon
8.8/10

Ease of Setup

Assembly
9.4/10
Karbon
7.9/10

Quality of Support

Assembly
9.5/10
Karbon
9.4/10

Assembly gives clients a branded, secure, all-in-one workspace

Assembly was designed for firms that care about client experience. Each client gets a white-label portal for messaging, document sharing, e-signatures, and payments—all with your firm’s branding. Karbon focuses more on internal collaboration and offers limited visibility to clients, requiring firms to juggle separate tools for communication, file sharing, and billing.

Secure document requests
Role-based permissions
White-label client portal
Real time chat for clients
Branded client-facing file storage hub
Progress and visibility tracking
Clients see tasks, statuses and progress
Self-serve payment links
Branded invoices + one-click payment links and subscriptions.

Assembly automates client workflows with deeper integrations.

Assembly connects your client operations end-to-end through powerful integrations and workflow automations. From onboarding and billing to reminders and document approvals, everything runs in one place. In contrast, Karbon’s automation is limited to internal task triggers and email workflows, with fewer client-facing automation options or open API capabilities.

Workflow automations
Task templates & reminders
Client reminder automations
eSignature automation
Custom data sync support
Automated client onboarding
Unified portal, forms, contracts, billing + full automation.
API & Webhooks
Full REST API + native webhooks for many events.
Multi-system integrations (Airtable, Calendly, ClickUp)
Plug-and-play integrations-easy setup for non-tech users.

Assembly delivers secure, structured file sharing built for client collaboration

Assembly offers a flexible file-sharing model with structured folders, secure document requests, instant notifications, and in-app previews, making external collaboration seamless without relying on email attachments. Clients get magic-link access with low login friction and can upload, view, and organize files in a branded, mobile-friendly interface. Karbon focuses primarily on internal file storage with limited client-facing file-sharing capabilities.

Structured folder organization
Secure document requests
Magic-link file access
In-app file previews
Instant document previews without downloads—faster client review and approval
Email + in-app notifications
Dual-channel notifications keep clients informed without inbox overload
Mobile-optimized file uploads
Fully optimized for mobile browser access
Client-facing file hub
Branded secure portal with instant client access

Assembly enables true client collaboration with visible, actionable task management

Assembly goes beyond internal task tracking by giving clients visibility into their tasks, threaded comments for collaboration, and automated reminders, reducing email back-and-forth and keeping projects moving. Task templates and checklists ensure consistency across client engagements, while clients can see real-time progress and next steps. Karbon excels at internal team workflows but offers limited client-facing task visibility and collaboration features.

Task templates & checklists
Internal task assignment
Automated task reminders
Client-visible tasks
Full task transparency keeps clients informed and engaged in real-time
Threaded task comments
Client-visible threaded discussions reduce email chains and keep context in one place
Client task collaboration
Clients can view, comment, and act on tasks directly in portal
Email-triggered task creation
Via Zapier/Make integrations and API
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Your clients deserve better than Karbon

Try Assembly for free, no credit card required.

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