Crossing 300 users on Microsoft 365 Business Premium: archive first

What happens to company records when a tenant outgrows Business Premium?

Microsoft 365 Business Premium is built for small organizations and carries a per-tenant user cap, commonly cited as 300 users; confirm the current figure on Microsoft's plan pages before you advise a client. A company or roll-up that passes the cap must move some or all users to an enterprise plan. That move touches mailboxes, retention settings and archives, so it is the right moment to preserve history and, for some companies, to ask whether the records qualify for a SourceX introduction.

This page is for MSPs and IT leads. It does not give licensing advice; plan features and limits change, so verify retention, archiving and export capabilities in Microsoft's current documentation.

What history a Microsoft 365 tenant holds

Depth varies by client. A tenant with a decade of mail and channels is different from one that was migrated last year and has only twelve months. The "years of history" question is the one that matters.

Why the 300-user crossing is a records event

Crossing the cap usually means a license change, a tenant restructure or a merger of acquired companies into one tenant. Each of those can alter what is retained.

• Migration between tenants: acquired companies may bring separate mail systems that get consolidated, sometimes with older mail left behind.
• License tier changes: retention and archiving options differ by plan, so default behavior may change after the move.
• Leaver cleanup: the rush to reduce license counts before the crossing often deletes mailboxes of departed staff.
• Mailbox size and shared mailboxes: large archives may be trimmed to speed up migration.

A company with fewer than the cap today may still be deleting history it will want later. For roll-ups, this is the stage where decisions about the archive of acquired companies are made, which ties directly to separating a shared email tenant after buying a business and to funding a partner buyout where one owner's mail leaves the tenant.

The archive-first checklist before the move

• Inventory every tenant, domain and shared mailbox, including those of acquired companies.
• Record the earliest data year per workload.
• Hold departed-user mailboxes until the company decides retention in writing.
• Confirm who owns global administrator rights and that a second named person can export.
• Take a documented export or backup of mail, chat and files before any cutover.
• Confirm the backup vendor's retention terms and how to retrieve data.
• Identify which data belongs to customers or third parties rather than the company.

Document each step. The paper trail is useful for operations and also supports a later records inventory.

Is a company at this size a SourceX candidate?

A tenant with hundreds of users may or may not reach 50+ full-time employees at peak, because user counts can include contractors, shared accounts and part-time staff. Headcount is only one part of the baseline. Other parts matter just as much: several years of documented operations, rights to license the data, and an authorized sponsor willing to consider an exclusive license for an agreed term. Read the who qualifies page. User count alone does not qualify a company.

Companies that look good have records across many systems, such as mail, chat, CRM, finance, support and engineering tools, plus archived history. Those that look poor have mostly client-owned data, deleted archives or no one who can export.

How an MSP spots a good candidate

1. During the license review, ask how many years of mail and Teams data exist.
2. Ask what other systems the client runs; most strong companies use 10-15+.
3. Note whether archived or retired systems still exist.
4. Ask whether an executive has authority to consider a data license.
5. If the answers look promising, raise it with the owner or CEO, not with end users.

You never open, export or describe client records for this purpose. The managed service provider playbook explains the role, and the roll-up context is in what AI roll-ups look for in acquisitions. A fractional CTO at a sponsor-backed company may also be your best contact; see fractional executives at search fund companies.

Pitfalls to avoid

How MSP rewards work

Partners earn 25% of the eligible platform fees SourceX actually collects from the referred company's licensing deals, capped at $100,000 per referred company. The reward is paid only after the buyer pays and SourceX receives its fee; an introduction, meeting or signed agreement alone does not trigger payment, and no reward is guaranteed. Review your client agreements for conflict and disclosure obligations before you register, and read the program terms.

Next step

Add three records questions to your next plan-cap review and use the network opportunity finder to think about which clients and roll-ups to raise it with. If a client fits, register as a partner and make the introduction.