Law Firm WIP and Receivables Days Calculator

The short answer

A law firm earns its fees long before it gets the cash. Time is first recorded but not billed (work in progress, or WIP), then billed but not paid (receivables). Add the two as days of your billings and you get your lock-up days, the length of time your money is waiting. This tool shows the days, the cash tied up, the yearly cost of carrying it, and what cutting a few days would free up.

Where to find the numbers

Number	Where it comes from
Fees billed per year	Fee revenue invoiced in the last 12 months, before disbursements, GST and trust money. From the billing or income report.
Unbilled time (WIP)	The dollar value of recorded time not yet on an invoice, from the WIP report in your practice management software.
Receivables by age	The accounts receivable aging report, fees only, in 0 to 30, 31 to 60, 61 to 90 and over 90 day buckets. Leave out trust money.
Your borrowing rate	The rate on your line of credit, or what the money could earn if it were in the bank.

Number

Where it comes from

Fees billed per year

Fee revenue invoiced in the last 12 months, before disbursements, GST and trust money. From the billing or income report.

Unbilled time (WIP)

The dollar value of recorded time not yet on an invoice, from the WIP report in your practice management software.

Receivables by age

The accounts receivable aging report, fees only, in 0 to 30, 31 to 60, 61 to 90 and over 90 day buckets. Leave out trust money.

Your borrowing rate

The rate on your line of credit, or what the money could earn if it were in the bank.

If this happens, then that

If…	…then
You bill more often	WIP days fall, because time spends less time waiting to go on an invoice. Monthly billing is a common habit.
You follow up on unpaid bills sooner	Receivable days fall and fewer invoices drift past 60 or 90 days.
Lock-up days keep growing	The firm is financing its clients. That can mean borrowing or leaving partner draws unpaid.
You add a retainer or deposit	Money in trust is not revenue, but deposits for fees can shorten the wait. Follow the Law Society trust rules.

If…

…then

You bill more often

WIP days fall, because time spends less time waiting to go on an invoice. Monthly billing is a common habit.

You follow up on unpaid bills sooner

Receivable days fall and fewer invoices drift past 60 or 90 days.

Lock-up days keep growing

The firm is financing its clients. That can mean borrowing or leaving partner draws unpaid.

You add a retainer or deposit

Money in trust is not revenue, but deposits for fees can shorten the wait. Follow the Law Society trust rules.

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Information only. General estimates and checklists, in 2026 dollars, using simplified assumptions. Not accounting, tax, legal or professional-regulatory advice. Rules and rates change, so confirm them with your regulator, the CRA, the BC government or your accountant.

Example numbers are made up. They only show how the tool works. Replace them with your own.

Want advice for your own situation?

This free tool is a courtesy of HJ Wu & Company Inc. (CPA), a Vancouver CPA firm offering accounting, tax, financial reporting and review assurance. Feedback on the calculators is welcome.