Migrate Azure AD B2C to Entra External ID
Plan a seamless CIAM cutover — just-in-time credential migration, dual-run, and rollback — without forcing every user to reset a password.
Book a migration readiness assessment
Step 1 of 2 — Your contact details
Outcomes from a British Columbia municipality migration
0
Forced password resets
Active residents migrated transparently as they signed in.
0
Service outages during cutover
Citizen-facing applications stayed available through dual-run.
0
Reset emails to residents
No mass “create a new password” campaign.
100%
Cutovers with a rollback path
Application-by-application cutover with rollback at every stage.
B2C support ends eventually — migrations do not fit in a weekend
Microsoft stopped creating new Azure AD B2C tenants and is investing CIAM capabilities in Microsoft Entra External ID. Existing B2C tenants keep running under a support window, but sitting still leaves you on a platform with no new features and a hard planning horizon.
Passwords in B2C are inaccessible hashes. A blunt “force everyone to reset” approach drives support spikes and abandoned accounts — especially painful for citizen, customer, and partner logins.
Multiple apps share one B2C tenant with custom IEF policies and claims.
No acceptable downtime for tax, billing, permits, or partner portals.
Legacy directory edge cases — duplicates, stale attributes — must be cleaned deliberately.
Stakeholders hear “supported until 2030” and under-estimate 3–12+ month migration work.
What a readiness-led migration covers
We treat this as a full system transition — not a tenant click-ops exercise. Scope is confirmed in assessment.
Entra External ID tenant setup
Stand up External ID experiences that match branding and user journeys before traffic moves.
Just-in-time credential migration
Validate legacy credentials at sign-in and establish External ID accounts in the same flow — no forced reset blast.
Dual-run & phased cutover
Run platforms in parallel and cut over application by application with a rollback path at every stage.
App token & policy integration
Rebuild journeys, claims, and token validation so multi-app tenants do not break mid-cutover.
JIT sign-in migration + dual-run cutover
Diagrams from the municipal CIAM engagement — first-party case-study art (SVG preferred for clarity).
Just-in-time migration
Unmigrated users authenticate against legacy B2C once; then credentials and account are established in External ID without a reset email.
Dual-run cutover
Both platforms operate in parallel while apps cut over one at a time — validating tokens before you commit.
Is this a fit?
We focus on organizations that need a production CIAM cutover with low citizen or customer friction — not DIY portal-only work.
Likely a fit
Still on Azure AD B2C with citizen, customer, or partner logins.
Multi-app shared tenant and/or custom IEF policies.
Public sector or regulated “no forced resets” requirement.
Need dual-run, rollback, and an application testing window.
Willing to start with a migration readiness assessment before build.
Likely not a fit
Greenfield Entra-only with no B2C tenant to leave.
Pure workforce Entra ID (not external CIAM).
Teams wanting DIY portal click-ops only — no engineering for apps or policies.
“Move everyone by Friday” with no dual-run or app validation window.
Looking only for Zero Trust workforce packaging (related, wrong message match).
Municipal CIAM: B2C → Entra External ID
We migrated a British Columbia municipality’s resident-facing identity platform from Azure AD B2C to Microsoft Entra External ID using JIT credential migration and a dual-run cutover — so residents kept signing in without reset emails or planned outages.
- Several city services shared one B2C tenant with custom policies and claims.
- JIT migration validated legacy credentials at sign-in and established External ID accounts in the same transaction.
- Directory cleanup (stale and duplicate records) happened on the way in, not as blind copy.
0
Forced resets
0
Cutover outages
0
Reset emails
100%
Rollback-ready cutovers
From readiness to dual-run cutover
Duration depends on app count, custom policies, and data quality — confirmed in your assessment.
Migration readiness assessment
Map tenants, apps, policies, and risk. Leave with a realistic picture of scope and sequencing.
- B2C / External ID footprint
- App & token inventory
- Risk & constraint list
- Recommended approach
External ID + JIT path
Configure External ID experiences and the secure migration service inside the authentication flow.
- Tenant & UX rebuild
- JIT migration service
- Claims / journey parity
- Pilot app validation
Dual-run cutover
Operate both platforms in parallel; cut over apps one at a time with rollback available.
- Parallel platforms
- App-by-app cutover
- Token validation gates
- Rollback rehearsals
Harden & handoff
Directory cleanup, modern MFA / risk signals where appropriate, and operational handoff.
- Stale/duplicate cleanup
- Security posture uplift
- Runbooks
- Post-cutover support
Questions we hear before assessment
Answers drawn from the case study and Entra External ID background — shortened for paid.
Microsoft supports B2C until 2030 — can we wait?
Existing tenants keep a support window, but CIAM migrations commonly take 3 to 12 months or longer. Identity is wired into apps and journeys; waiting until the last year leaves little room for dual-run testing and stakeholder “no disruption” requirements.
Why not force password resets?
Forced resets create support spikes, lockouts, and abandoned accounts. A just-in-time path validates credentials against B2C at sign-in and establishes External ID credentials in the same flow so active users continue without inventing a new password.
Is standing up a new tenant enough?
Usually not. Multi-app token validation, custom IEF policies, and claims rarely translate one-to-one. Dual-run and per-app cutover are how you prove each application before you commit.
Is downtime inevitable?
It does not have to be. Dual-run with application-by-application cutover and a rollback path at every stage kept citizen-facing apps available in the municipal engagement we document.
What happens in a migration readiness assessment?
We review your B2C tenant footprint, apps, policies, and constraints, then outline scope, risk, and a realistic timeline for JIT migration and dual-run — before you commit to build work.
How this compares
Seamless CIAM transition vs reset blasts or config-only projects.
| Feature | Mars Innovation Technology | Generic Consultancy | DIY / In-House |
|---|---|---|---|
JIT / seamless credential path | ✓ | Often force resets | ✗ |
Dual-run with rollback | ✓ | Rare | ✗ |
Multi-app token & policy work | ✓ | Tenant-only focus | Partial |
Public-sector friction constraints | ✓ | Varies | ✗ |
Readiness assessment before build | ✓ | ✗ | ✗ |
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