Switching Legal Software: A Migration Guide for Law Firms

Changing your practice management or case management system is one of the most disruptive technology projects a law firm will undertake. Done badly, it causes billing gaps, data loss, compliance failures, and significant staff frustration. Done well, it unlocks years of efficiency gains and positions the firm for growth.

The bad news is that legal software migrations are frequently done badly. A survey by the Legal Software Suppliers Association found that over 60% of law firm software projects overrun their original timeline, and nearly half exceed their budget by more than 20%. The most common cause is not poor software — it is insufficient planning.

This guide gives you the framework to be in the successful minority.

Why Firms Switch Legal Software

Before committing to a migration, it is worth being clear about why you are switching. The most common drivers are:

The existing system no longer scales: the firm has grown and the software cannot handle the volume of matters, users, or complexity
Compliance gaps: the platform cannot support LAA CCMS billing, SRA Accounts Rules reconciliation, or AML obligations adequately
Poor time recording: fee earners are losing billable time because the recording tools are clunky or manual
Vendor issues: price increases, poor support, or a vendor that has stopped investing in the product
Merger or acquisition: two firms coming together on different systems need to converge

Understanding your primary driver shapes your migration priorities. If billing leakage is the problem, time-recording capability should be your top evaluation criterion in the new platform. If you are merging two firms, data integrity and the ability to import from both legacy systems matters most.

Phase 1: Planning (8–12 Weeks Before Go-Live)

Define the Scope and Non-Negotiables

Start by producing a requirements document. Do not let vendors write this for you — they will write it to favour their own platform. Your requirements document should cover:

Matter types and volumes: what practice areas do you run, how many open matters per fee earner, and what are the typical workflows?
Billing model: fixed fee, hourly, legal aid, or mixed? What billing frequencies do you operate?
Regulatory obligations: which LAA contract types do you hold? Do you need CCMS integration? What AML processes must be supported?
Integration requirements: which third-party systems (Land Registry, Companies House, SDLT, court portals, DocuSign) must be connected on day one?
Reporting requirements: what financial and operational reports do partners rely on monthly?

Assign each requirement a priority: must-have, should-have, or nice-to-have. Any platform that cannot meet your must-have list should be eliminated from the shortlist regardless of price or sales pitch.

Audit Your Current Data

This step is skipped by most firms and is the biggest cause of migration problems. Before you touch the new system, produce a data audit of your current platform covering:

Open matters: how many are open, when were they last updated, are they all correctly assigned to fee earners?
Client records: are there duplicates? Are contact details current? Which clients have active retainers?
Financial data: what is your WIP balance? Are all client ledgers reconciled? Are there residual balances on client account?
Documents: how many documents are stored, how are they organised, and are there orphaned documents not linked to matters?

The data audit typically reveals that 15–30% of open matters have incomplete or inaccurate records. Migrating dirty data into a new system does not clean it — it just moves the mess. Invest time cleaning your data before migration begins.

Select Your Migration Partner

Unless you are a very small firm migrating a small dataset, you should engage a specialist legal IT consultant or the professional services team of your new vendor for the migration. The cost — typically £5,000–£25,000 depending on complexity — is almost always recovered within a few months by avoiding the productivity loss of a poorly executed cutover.

When selecting a migration partner, ask specifically:

How many migrations from your legacy system have you completed?
What data do you not migrate (and why)?
What is your approach to validation — how will we know the migrated data is accurate?
What is the rollback plan if the migration fails?

Phase 2: Parallel Running (4–6 Weeks Before Go-Live)

Set Up the New System

Work with your vendor to configure the new platform before any data migration begins. This includes:

Chart of accounts: set up your nominal codes, VAT rates, and bank accounts to match your existing accounting structure
Fee earner profiles: create user accounts, set billing rates, and configure access permissions
Matter templates: build the matter types, task lists, and document templates your fee earners will use daily
Workflow automation: configure any automated tasks, reminders, and escalations

Do not go live on default settings. The out-of-box configuration of most legal platforms is designed to be inoffensive to the broadest range of firms, not optimised for yours.

Run a Pilot Migration

Before migrating your full dataset, run a pilot migration with a sample of your data — typically 50–100 matters representing your main practice areas. Validate the migrated data against the source system:

Do matter balances match?
Are all documents accessible and correctly linked?
Do client ledgers balance correctly?
Are fee earner time records intact?

Document every discrepancy. Some will be acceptable (for example, if the legacy system stored document metadata that the new system handles differently); others will require the migration script to be adjusted.

Staff Training

The biggest predictor of post-migration success is training. Firms that invest properly in training — typically 2–3 days per staff member for the core system, with additional role-specific training for accounts staff and partners — achieve full productivity within 4–6 weeks of go-live. Firms that rely on a 2-hour webinar and a manual are still fighting the system six months later.

Structure training in this sequence:

System familiarisation: navigating the interface, finding matters, opening documents
Day-to-day tasks: the specific workflows each role will use every day (time recording, document filing, correspondence)
Billing and accounts: the financial workflows, which should always involve your accounts staff and a qualified legal cashier
Exception handling: what to do when something goes wrong — how to raise a support ticket, who to call, and what the escalation path is

Keep training sessions to half-days maximum. Full-day sessions in software training have sharply diminishing returns after four hours.

Phase 3: Cutover and Go-Live

Choose Your Cutover Date Carefully

The best cutover dates are:

After a reconciliation date: if your SRA Accounts Rules reconciliation falls on the last day of the month, go live on the first working day of the following month with a clean reconciled balance
During a quieter period: avoid the week before a major court deadline, during a conveyancing completion rush, or in the run-up to a legal aid billing deadline
On a Thursday or Friday: counterintuitively, mid-week cutover often works better than Monday — you get two days to identify and fix critical issues before the full week begins

Freeze the Legacy System

On cutover day, freeze the legacy system: no new time entries, no new billing, no new matter opening. Take a final backup. This is your safety net.

Validate the Final Migration

Before allowing fee earners onto the new system, your accounts team and IT lead should run through the validation checklist:

Total WIP in new system matches legacy system as of cutover date
Client account balance matches reconciled legacy balance
All open matters present and assigned to correct fee earners
All documents accessible
Email integration connected and routing correctly
Reporting producing expected outputs

Do not declare go-live until this checklist is complete.

Common Migration Mistakes and How to Avoid Them

Migrating Too Much Historical Data

Firms often want to migrate 10+ years of closed matter history. This is rarely worth the cost and complexity. A better approach: migrate all open matters fully; migrate closed matters from the last 3–5 years in summary form (no documents, just the key financial records); archive older data in the legacy system with read-only access for a further 2 years, then decommission.

Underestimating the Accounts Migration

The financial data migration is always the hardest part. Client ledger balances must be exactly correct — a penny-level discrepancy in client account is a compliance issue, not just an inconvenience. Budget twice as much time for accounts migration validation as you think you need.

Not Testing Integrations

Third-party integrations — Land Registry, SDLT, DocuSign, Xero — are often the last thing tested and the first thing to break in production. Build integration testing into your pilot phase, not as an afterthought after go-live.

Neglecting the Parallel Running Period

Some firms go straight from training to live cutover. This is high risk. Even a 2-week period of parallel running — where a small group of early adopters uses the new system on real matters while the legacy system remains live — reveals configuration problems and training gaps before they affect the whole firm.

Managing the Human Side of Migration

Technology migrations are as much a people challenge as a technical one. Fee earners who are forced to change systems they have used for years will find fault with the new platform regardless of its objective quality. To manage this:

Involve fee earners early: include at least one partner and one senior associate in the evaluation and configuration process. People support what they help build.
Identify and cultivate champions: find the tech-enthusiastic fee earners in each department and give them early access. Their peer endorsement is more powerful than any vendor training.
Communicate the benefits in their terms: partners care about lock-up ratios and WIP visibility. Associates care about time recording not being a chore. Communicate to each group in their own language.
Acknowledge the difficulty: it is a significant change. Pretending it is easy breeds cynicism when it turns out to be hard.

After Go-Live: The First 90 Days

The migration is not complete on go-live day. Plan for:

Daily support calls for the first two weeks: a brief 15-minute call with your vendor or migration partner to surface and resolve issues before they compound
Week 3–4 accounts review: your legal cashier should run a full reconciliation in the new system and compare to the legacy system
30-day productivity review: compare time recorded and bills raised in the first month post-migration to the equivalent period pre-migration; investigate any significant drops
60-day decommission decision: at 60 days, assess whether you are ready to decommission the legacy system or whether you need a further period of read-only access

Switching legal software is a significant project, but firms that plan it properly consistently report that the productivity and compliance benefits materialise within six months. The key is treating it as a change management project, not just a technology project.

Obiter works alongside whatever practice management platform you land on. Its AI reads your email, drafts correspondence for fee earner approval, and automatically records billable time — ensuring that the time you invest in a new system is not undermined by the manual administrative overhead that has always sat outside most PMS platforms. If you are re-evaluating your tech stack, it is worth seeing what Obiter adds to the picture. Start a free 14-day trial at obiteros.com.