# Tenant-to-Tenant Migration Timeline Estimator

Estimate the planning complexity of a Microsoft 365 tenant-to-tenant migration.

## How many users are moving?

Include active users, shared mailboxes, guests, and external collaboration needs.

- Under 100 users
- 100-1,000 users
- 1,000+ users

## How many workloads are in scope?

Mail, OneDrive, SharePoint, Teams, groups, devices, apps, and Power Platform each add sequencing requirements.

- Mail only or limited scope
- Mail plus files/sites
- Full tenant move

## How complex is identity?

Consider domains, Entra ID, synchronization, Conditional Access, MFA, devices, and administrative roles.

- Simple cloud identity
- Hybrid or multiple domains
- Complex identity and security dependencies

## How much data is involved?

Storage volume affects tool selection, wave sizing, throttling, and validation.

- Low volume
- Moderate volume
- High volume or sensitive data

## Is coexistence required?

M&A and divestiture projects often require mail routing, address book, collaboration, and staged cutover decisions.

- Single cutover acceptable
- Short coexistence window
- Long or complex coexistence

## How fixed is the deadline?

Legal, brand, acquisition, or contract dates can reduce flexibility.

- Flexible
- Target date within 3-6 months
- Fixed or urgent cutover date