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Blog · Board and management reporting · Law firms

Lock-up on five clients: the whole arithmetic on one page

The complete lock-up calculation on five clients of a professional firm, small enough to check by hand: worked value from time entries, billed from bills, received from receipts, unbilled WIP and outstanding debtors, average daily billing, WIP days, debtor days, lock-up days and lock-up cash, the split that says whether the delay is billing or collection, the practice norm, and the identity that WIP and debtors reconcile, so a reader can reproduce every figure and then run it on their own practice management exports.

The short answerFive clients over a year. Worked value is hours times standard rate from time entries; billed is the sum of bills; received is the sum of receipts. Unbilled WIP is worked less billed; outstanding debtors is billed less received. Average daily billing is billed over 365. WIP days is unbilled WIP over daily billing; debtor days is debtors over daily billing; lock-up is the sum. Two clients have similar lock-up near 190 days: one because the partner bills twice a year, one because the client pays on chase. The split names the lever. Every number can be reproduced by hand.

Lock-up is the time between work done and cash received, and on five clients every step can be checked. This page works WIP, debtors, the days, the cash, the split, the norm and the identity.

The rows

Client Worked (hours × rate) Billed Received
A $1,900,000 $1,460,000 $1,410,000
B $1,200,000 $1,180,000 $760,000
C $640,000 $600,000 $520,000
D $400,000 $390,000 $385,000
E $300,000 $150,000 $150,000

WIP and debtors

Unbilled WIP = worked − billed; outstanding debtors = billed − received

Client Unbilled WIP Debtors Daily billing (billed ÷ 365)
A $440,000 $50,000 $4,000
B $20,000 $420,000 $3,233
C $40,000 $80,000 $1,644
D $10,000 $5,000 $1,068
E $150,000 $0 $411

The days and the cash

WIP days = WIP ÷ daily billing; debtor days = debtors ÷ daily billing; lock-up = sum; cash = WIP + debtors

Client WIP days Debtor days Lock-up days Lock-up cash Practice norm Split
A 110 13 123 $490,000 95 Billing
B 6 130 136 $440,000 95 Collection
C 24 49 73 $120,000 95 On norm
D 9 5 14 $15,000 95 Fine
E 365 0 365 $150,000 95 Billing: half the year's work unbilled

Client A: the partner has not billed $440,000 of work; the client pays in two weeks when asked. Client B: billed promptly, paid four months late. Similar lock-up, opposite levers. Client E: a year of unbilled work on a small client, which is either a fixed fee not yet invoiced or a matter nobody has closed.

The identity

Σ WIP = Σ worked − Σ billed = 4,440,000 − 3,780,000 = $660,000 Σ debtors = Σ billed − Σ received = 3,780,000 − 3,225,000 = $555,000 lock-up cash across the five = $1,215,000

Both reconcile to the practice's WIP and debtor ledgers, or the difference is a bill or receipt unmatched.

Where it goes wrong, even at five

Firm-level lock-up. A weighted average near 110 days; A and B invisible.

Days blended. A and B look alike; the fix for each is the other's.

No cash figure. A hundred and twenty-three days does not persuade a partner; $490,000 does.

E unread. Small client, small daily billing, 365 days: the largest ratio on the page and the one most likely to be a write-off waiting.

From five to five hundred

The same three sums per client, the same two divisions, the practice norm from the book, the split. Covirage runs it on the time entries, bills and receipts every month. The lock-up guide covers the measure, and the realisation guide covers the other leak in the same exports.

Questions people ask

Why average daily billing as the divisor?

Because it puts WIP and debtors on the same scale, days of billing, so a client with large fees and a client with small ones can be compared. It is the standard measure; the matter-level dates give the same answer another way and are shown where the data allows.

What is the norm?

The practice's own median lock-up across its clients, here 95 days. A client at 190 is twice the norm; the split says whether to talk to the partner or to credit control.

What about write-offs?

Worked value that will never bill is written off and removed from WIP with a reason. This page has none; on a real book the write-off is its own line and the identity carries it.