# Sei vs Kastle

*Voice Agents · Sei vs Kastle*

> Kastle focuses on AI voice agents for mortgage servicing. Sei covers servicing and origination voice and adds the loan manufacturing in between — underwriting, income calculation, closing, and QC — on one managed platform.

Kastle and Sei both run compliant AI voice agents for borrower calls, and both target mortgage. Kastle concentrates on the servicing side — payments, escrow, retention, and early-stage collections — across multiple channels.

Sei runs voice across the whole lifecycle and pairs it with the loan operation. Servicing agents handle payoffs, due-date changes, and FDCPA-compliant hardship calls; origination agents run speed-to-lead and book loan-officer appointments; and the same managed platform underwrites the file with rep-and-warrant-eligible income, automates the Closing Disclosure, and clears post-close QC.

## What Kastle does

Kastle provides AI voice agents that automate high-volume borrower servicing calls — payments, escrow, retention, and early-stage collections — across voice, text, email, and webchat.

## Sei vs Kastle

| Dimension | Sei | Kastle |
| --- | --- | --- |
| Servicing & collections voice (FDCPA) | Yes | Yes |
| Inbound sales + speed-to-lead voice | Yes | Limited |
| Loan-officer appointment booking | Yes | No |
| 100% call QA (TILA/RESPA/TRID) | Yes | No |
| Document intelligence & underwriting | Yes | No |
| Income calc + Fannie Income Calculator (rep & warrant) | Yes | No |
| Closing Disclosure automation & post-close QC | Yes | No |
| End-to-end, fully managed | Sales → servicing | Servicing voice focus |

_Comparison as of June 2026. Kastle: https://www.kastle.ai/_

## Why teams pick Sei

- **Voice across the whole lifecycle** — Speed-to-lead and 24/7 inbound sales agents, loan-officer appointment booking, and FDCPA-compliant servicing and collections — borrower conversations from first contact through payoff, on one platform.
- **Rep-and-warrant-eligible income** — Income is calculated across W-2, self-employed (Schedule C, K-1, S-corp, 1099), rental, and retirement income, with Fannie Mae Income Calculator integration — so eligible calculations earn representation-and-warranty relief and lower repurchase risk.
- **Fully managed, end to end** — Sei builds, deploys, and runs the agents and workflows for you — from the first sales call through underwriting, closing, and post-close QC. You get outcomes, not a toolkit to configure, typically live in weeks.

## Where Kastle is strong

- Strong, focused servicing automation across call, text, email and webchat
- Integrations with servicing systems of record, including ICE MSP
- Built for high-volume servicing and payment conversations

## When Sei is the better fit

- You want voice on both origination and servicing from one platform
- You also need underwriting, income calculation, closing and QC
- You want 100% call QA against TILA, RESPA, TRID and UDAAP

## FAQ

**Is Sei a fit for mortgage servicing like Kastle?**

Yes. Sei’s voice agents handle servicing calls — payments, payoffs, due-date changes, hardships, and FDCPA-compliant collections — and also cover origination, underwriting, closing, and QC on the same managed platform.

**Does Sei integrate with servicing systems?**

Yes. Sei integrates with ICE and other loan-management systems, CRMs, and telephony/CCaaS platforms, with custom integrations supported during onboarding.

**What does Sei add beyond servicing voice?**

Origination sales voice with LO appointment booking, document intelligence and underwriting, income calculation for rep-and-warrant relief, Closing Disclosure automation, and pre/post-close QC.

**What certifications does Sei hold?**

Sei is SOC 2 Type II and PCI DSS Level 1 certified, deploys in private VPCs, and never trains on your data.

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_Source: [https://www.seiright.com/comparisons/sei-vs-kastle](https://www.seiright.com/comparisons/sei-vs-kastle) · Sei AI_