Letterbook vs Siena AI

See how their public offers line up before you choose your own position. Prices stay in the currency, billing schedule, and charged unit each vendor publishes.

Letterbook

See full pricing history

USD · US · source: www.letterbook.ai

Plan	Pricing	Charged by	Offer type
Starter — default	USD 50 monthly · USD 50 / month with annual commitment $50 per month	Flat · per month	Standalone · Fixed
Growth — default Highlighted	USD 200 monthly · USD 200 / month with annual commitment $200 per month	Flat · per month	Standalone · Fixed
Enterprise — default	Contact sales Let's talk per month	Flat · per month	Standalone · Contact sales

Siena AI

See full pricing history

USD · US · source: www.siena.cx

Plan	Pricing	Charged by	Offer type
Platform fee — Core AI engine and unlimited sandbox	USD 750 monthly $750/month	Flat · per month	Standalone · Fixed
Automation Pack — Ticket automation	USD 0.9 monthly $0.90 each	Usage · per ticket	Standalone · Usage based

What each plan includes

Feature names follow each vendor’s own pricing page, so verify the wording before treating them as exact equivalents.

Letterbook

Starter — default

Highlights Seats: 3 seats

Included
Highlights Tickets per month: 300 tickets / month

Included
Highlights Integrations: Integrate your database & Stripe

Included
Highlights Inbox: Unified inbox for all your channels

Included

Growth — default

Highlights Seats: 10 seats

Included
Highlights Tickets per month: 1,000 tickets / month

Included
Highlights Channels and integrations: All channels and integrations

Included
Highlights Support: Priority support

Included

Enterprise — default

Highlights Seats: Custom seats

Included
Highlights Tickets per month: 3,000+ tickets / month

Included
Highlights Security: SSO & SAML

Included
Highlights Account management: Dedicated account manager

Included

Siena AI

Platform fee — Core AI engine and unlimited sandbox

Highlights Access to Siena’s core AI engine: Included
Highlights Unlimited sandbox: Included

Automation Pack — Ticket automation

Highlights Automate tickets: Included

How their prices changed

Each dated row shows the public prices observed when that vendor’s pricing page changed.

Letterbook

August 27, 2026 Source
- Starter — default: USD 50 monthly · USD 50 / month with annual commitment
- Growth — default: USD 200 monthly · USD 200 / month with annual commitment
- Enterprise — default: Contact sales

Siena AI

August 27, 2026 Source
- Platform fee — Core AI engine and unlimited sandbox: USD 750 monthly
- Automation Pack — Ticket automation: USD 0.9 monthly