What Would You Charge for Migrating a 10-Person CPA Firm from On-Premises to the Cloud?

I would avoid a completely open-ended flat fee unless you can define every assumption. Break the project into separate work packages—discovery and design, cloud setup, security and permissions, application configuration, file migration, workstation work, testing, training, and documentation. Give each package an estimate and clearly state what happens if the assumptions are wrong. A time-and-materials project with a not-to-exceed amount, or a flat fee with change-order language, is usually safer.

One hundred hours sounds very light for doing this properly. The user count is small, but the work does not shrink proportionally with the number of employees. Networking, identity, permissions, security policies, application dependencies, migration testing, rollback planning, and training can take substantial time. I’d think in terms of a multi-month project timeline rather than assuming it can be finished in a week or two, especially if you’re doing it alongside your regular job.

A cloud desktop environment such as Azure Virtual Desktop could potentially be delivered as a roughly $10,000–$15,000 project for a firm this size, but that is only a rough comparison. The final price depends heavily on whether the applications work cleanly in the target environment, how complicated the folder permissions are, how much data needs to be cleaned up, and how much hand-holding the users require. Price the discovery phase first if the environment is poorly documented, then provide a more reliable implementation estimate.

Before quoting, define what is included in the migration: number of testing rounds, data cleanup, backup retention, workstation disposal, after-hours cutover, user training sessions, support after launch, disaster recovery documentation, and rollback. Put exclusions and hourly rates in writing. If you still choose a flat rate, add a healthy contingency—possibly two or three times the optimistic estimate—and require written approval for anything outside the assumptions.

Do not treat the permissions rebuild as a minor part of the file copy. Someone will need to interview the partners and staff to determine who should access which client folders, and older firms often have little documentation. Scope that separately from the 4 TB migration.

Also verify the exact QuickBooks Desktop editions and versions before committing to a price. Unsupported versions or upgrades can become their own project. Since this is a tax and accounting firm, check whether they have a written information security program, named security responsibility, incident response procedures, and other safeguards documentation. Creating that program may be valuable work, but it should be explicitly included as a separate deliverable rather than treated as incidental configuration.