Write-Off vs Write-Down in Agency Billing
In agency billing, a write-off and a write-down both reduce the revenue an agency collects — but they happen at different stages and for different reasons. A write-down is a billing decision made before or when the invoice goes out. A write-off is a collection decision made after an invoice goes unpaid.
What a write-down is
A write-down in agency billing reduces the invoice amount below what logged hours would fully justify. The work happened. The hours were real. But the agency bills less than the full amount — because the project ran over through no fault of the client, because the scope was agreed at a fixed price, or because the relationship value outweighs the overage.
Write-downs are common in fixed-fee work: the agency estimates 30 hours, spends 40, and bills for 30. The gap — 10 hours at whatever the bill rate is — is an internal write-down. It doesn't appear on the invoice. It does appear in the gap between what the agency earned on paper and what it billed. That gap is what lowers the agency's realization rate.
What a write-off is
A write-off in agency billing removes an unpaid receivable from the books. The work was done. The invoice was sent. The client didn't pay, isn't going to pay, and further collection effort isn't worth it. The invoice is written off — moved from accounts receivable to bad debt expense.
Write-offs are the end stage of a collection failure. They are distinct from disputes resolved with a credit note (where the agency reduces or cancels an invoice and the client relationship continues). A write-off typically follows a non-responsive or insolvent client after 60–90 days past due.
Write-offs vs write-downs: at a glance
| Term | Stage | What happens |
|---|---|---|
| Write-down | Pre-invoice or at invoice time | Bill a lower amount than hours logged justify |
| Write-off | Post-invoice, post-collection attempt | Remove an unpaid invoice from receivables as a loss |
| Discount | Pre-invoice | Intentional price reduction, not related to over-run or non-payment |
| Credit note | Post-invoice | Reduces or cancels a previously issued invoice (client relationship continues) |
Worked examples
Write-down example. A dev studio quotes 20 hours for a feature build. The work takes 28 hours due to a technical complication the studio considers its own scoping error. Rather than billing the client for 28 hours, the studio sends an invoice for 20 hours and writes down the 8 extra hours. Those 8 hours happened but weren't billed.
Write-off example. A marketing agency completes a $3,200 campaign setup and invoices the client. The client disputes the invoice, stops responding after 90 days, and the agency determines collection is not worth pursuing. The $3,200 is written off — moved from accounts receivable to bad debt expense.
Why the distinction matters for agency finances
Frequent write-downs point to a scoping or pricing problem — the agency consistently underestimates work, over-delivers without billing, or absorbs client-requested changes. The fix is better estimates, clearer change-order processes, or a rate increase.
Frequent write-offs point to a client-selection or collection problem — the agency takes on clients who don't pay, doesn't collect deposits, or lets invoices age too long before escalating. The fix is better client vetting, upfront deposits, and tighter payment terms.
Every write-down also reduces the agency's effective billing rate on the project and the practice's overall realization rate. An agency writing down 10% of its logged hours every month has a realization rate ceiling of 90% before any other billing friction.
Frequently asked questions
What is the difference between a write-off and a write-down in agency billing?+
A write-off removes an unpaid invoice from accounts receivable after deciding it won't be collected — the work was done and invoiced but not paid. A write-down reduces the invoice amount before or at sending — the work was done but the agency bills less than the full logged hours justify.
When should an agency write down hours?+
When the project ran over due to factors the agency considers its own responsibility (underestimating, rework, internal inefficiency) and the agency made a fixed-price or capped commitment. Writing down hours is preferable to billing a client for overruns they weren't warned about.
When should an agency write off an invoice?+
After a reasonable collection period has passed — typically 60–90 days past due — and the client is non-responsive or insolvent. Writing off sooner is premature; writing off later just delays recognising the loss.
How do write-offs affect agency profitability?+
A write-off converts an accounts-receivable asset to a bad-debt expense in the same period. It reduces net income. For cash-basis agencies, it still represents a real loss of work performed without compensation.
What is the connection between write-downs and realization rate?+
Every hour written down is an hour worked but not billed — that gap directly lowers the agency's realization rate. An agency writing down 10% of logged hours every month has a realization rate ceiling of 90% before considering any other billing friction.
Is a write-down the same as a discount?+
No. A discount is an intentional pricing decision made upfront. A write-down is typically a post-scoping adjustment — the hours were logged at full rate, then the invoiced amount was reduced. Both lower realised revenue, but they arise from different causes.
Can a change order prevent a write-down?+
Yes — that's the point of a change order. When a client requests work outside the agreed scope, a change order documents the addition and bills for it, rather than absorbing the hours and writing them down later.
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