Lawyers lose 10-30% of billable time to write-downs — clients cutting vague time entries like “research” or “review documents.” AI generates specific, detailed billing descriptions that justify every hour and reduce write-downs significantly.

The billing description prompt

``` Prompt: “Convert these rough time notes into professional billing entries.

Notes:

• 45 min: looked at contract, found issues with indemnification
• 1.5 hr: called client about settlement offer, discussed options
• 30 min: emails with opposing counsel about discovery deadline

For each entry, provide:

• Time (in 0.1 hour increments)
• Detailed narrative (specific enough to justify the time)
• Task code (if applicable)

Rules:

• Be specific: ‘Reviewed and analyzed indemnification provisions in Service Agreement’ not ‘Reviewed contract’
• Include what was accomplished, not just what was done
• Use active voice
• Don’t pad — keep descriptions honest but thorough” ```

Before and after

Rough note	AI billing entry
”Research” (1.0)	“Researched applicable statute of limitations for breach of fiduciary duty claims under [State] law; analyzed recent appellate decisions regarding tolling provisions” (1.0)
“Call with client” (0.5)	“Telephone conference with client regarding settlement offer from opposing party; discussed terms, risks of proceeding to trial, and recommended counter-offer strategy” (0.5)
“Emails” (0.3)	“Correspondence with opposing counsel regarding extension of discovery deadline; negotiated revised schedule for document production” (0.3)

The AI version is harder for clients to cut because it shows exactly what was done and why it mattered.

End-of-day time capture

Most lawyers forget to log time during the day. At 6 PM, they reconstruct from memory and lose 15-20% of billable time.

``` Prompt: “I’m a [practice area] lawyer. Here’s what I did today (rough notes from memory):

[paste rough notes, emails sent, calls made, documents reviewed]

Reconstruct my timesheet for today. For each entry:

• Estimate time in 0.1 hour increments
• Write a detailed billing narrative
• Assign to the correct client/matter
• Flag anything that might be non-billable” ```

Invoice narrative generation

For monthly invoices that need a summary:

``` Prompt: “Write an invoice cover letter summarizing this month’s legal work.

Client: [name] Matter: [description] Total hours: [X] Total fees: $[amount] Key activities this month: [list major tasks] Status: [where the matter stands] Next steps: [what’s coming]

Tone: professional, transparent about the work done. Justify the fees without being defensive.” ```

Tools for AI-powered legal billing

Tool	What it does	Price
Clio	Practice management + AI time capture	From $39/mo
TimeSolv	Legal billing + AI descriptions	From $40/mo
Smokeball	Auto time tracking + AI narratives	From $29/mo
ChatGPT	Convert rough notes to billing entries	Free / $20/mo

Smokeball is notable because it automatically tracks time based on your activity (documents opened, emails sent, calls made) — no manual entry needed. AI then generates the billing descriptions.

Reducing write-downs

The formula: specific descriptions + reasonable time + clear value = fewer write-downs.

``` Prompt: “Review these billing entries and flag any that a client might challenge or request a write-down:

[paste entries]

For each flagged entry:

• Why it might be challenged
• How to rewrite it to be more defensible
• Whether the time seems reasonable for the task” ```

Related: AI for Lawyers: Document Review · AI Contract Drafting · AI Legal Client Intake · Clio Duo vs PracticePanther · 7 Best AI Tools for Lawyers