When the spreadsheet stops being enough.

Why the spreadsheet works at first

A spreadsheet is not a naive choice. It is free, instant, infinitely flexible, and shaped exactly like your practice because you shaped it. For the first twenty or thirty matters it genuinely is the right tool, and anyone who tells you otherwise is selling something.

What changes is not the number of matters. It is the number of things you have to remember about each matter.

What actually breaks, and in what order

First: dates stop chasing you

A spreadsheet is passive. It will hold a notice expiry date perfectly well, and it will hold it just as calmly on the day it passes. Every deadline you meet is one you personally remembered to look for. That works until the week you are ill, on holiday, or simply busy on another matter — and the failure mode is not a gentle one, because the dates that matter most in litigation and possession work are precisely the ones with consequences attached.

Second: billing forks into two versions

This is usually the one that forces the move. You have what you have billed, and you have what the firm owes you, and under a fee-share arrangement these are different numbers with different timings. In a spreadsheet they become different tabs, then different files, then a monthly reconciliation you do by hand and never entirely trust. If you have ever finished that reconciliation and thought "close enough", the sheet has already stopped being a system of record.

Third: you quietly stop maintaining it

The final stage is the dangerous one. Updating falls behind, and because the sheet still opens and still looks complete, it keeps the appearance of authority while the real state of your caseload lives in your head and your inbox. A register nobody trusts is worse than no register, because it invites decisions based on stale figures.

Moving across without losing a week

The mistake is treating this as a data migration project. It is not — you do not need to move history, and trying to is what turns an afternoon into a fortnight.

• Bring across open matters only. Closed matters are archive; they can stay in the spreadsheet indefinitely. Most consultants have far fewer genuinely live matters than the sheet's row count suggests.
• Set up your key dates before you enter anything. Decide what dates your work actually turns on, and name them first. Entering matters before the date fields exist means entering them twice.
• Define one workflow, for your most common work type. Not all of them. Get one right, run real matters through it for a fortnight, and let the others follow once you know what you actually wanted.
• Start billing from a clean month boundary. Do not try to reconstruct part-billed months. Draw a line, close the old month in the spreadsheet, and start the new one in the system.
• Keep the spreadsheet read-only for a month. Not as a fallback you keep updating — as a reference you can check against. If you maintain both, you will end up trusting neither.

What you should expect to feel

For about two weeks it will feel slower, because entering a matter properly takes longer than adding a row. The return arrives the first time the system tells you something you did not know — a date approaching on a matter you had not thought about, or a firm that is a month behind paying an invoice you had assumed was settled.

One honest caveat: your files do not move. The Casebook stores no client documents by design — they stay in whatever document store you or your billing firm already use. What moves is the register: matters, clients, key dates, workflow and money. If you were hoping a single migration would also tidy your document storage, that is a separate project, and conflating the two is a reliable way to finish neither.