My Domain setup has four phases: request the name, test in parallel, deploy live, and audit for impacts. Plan a release cycle from request to live, with active communication to users and integration owners.
- Pick the My Domain name
Setup, Company Settings, My Domain. Enter the desired subdomain (acme, acme-prod, brandname). Salesforce checks availability; names are first-come-first-served across the platform. Avoid names that conflict with trademarks or other brands.
- Request and wait for DNS propagation
After submission, Salesforce provisions DNS records. Propagation takes up to 24 hours. During this window the new URL works for testing but the old URL is still primary. Verify the new URL resolves and the test login page loads.
- Test in parallel
Log in via the new URL. Verify SSO, integrations, Lightning Web Components, and external links work. Test as multiple user profiles. Document any breakages and fix before deployment.
- Deploy My Domain live
Setup, My Domain, Deploy to Users. The new URL becomes primary; old URLs redirect. Every active session is invalidated; users must log in again. Communicate the timing to users 24-48 hours ahead.
- Audit for hardcoded URLs
Apex code, Visualforce pages, integrations, email templates. Find any hardcoded references to the old na123 or eu5 pattern. Replace with dynamic URL retrieval via System.URL.getOrgDomainUrl() or external configuration.
The branded part of acme.my.salesforce.com. First-come-first-served across the platform; cannot be changed after activation without a deployment.
Some orgs see acme.lightning.force.com for the Lightning UI alongside acme.my.salesforce.com for Classic-pattern URLs. Both resolve to the same org.
Beyond My Domain, configure a customer-owned domain (app.acme.com) for higher-tier branding.
Salesforce''s newer URL pattern that consolidates several legacy subdomains. Auto-applied to most orgs; check Setup, Enhanced Domains for status.
- Deployment invalidates every active session. Communicate timing to users 24-48 hours ahead to avoid support ticket surge.
- SSO providers need reconfiguration when My Domain changes. Coordinate with the IDP team; SAML and OAuth registrations all reference the My Domain URL.
- Hardcoded URLs in Apex, Visualforce, and integrations break after activation. Audit thoroughly; use dynamic URL retrieval methods.
- Subdomain names are first-come-first-served and cannot be changed easily. Pick carefully on initial request.
- The Custom Domain upgrade requires DNS ownership and certificate management. More setup work than My Domain alone.