InvoiceFlow for Lawyers: Complete Billing Guide

The invoicing system built for solo attorneys, small law firms, legal consultants, and independent legal professionals

Legal billing requires per-matter invoicing, retainer replenishment tracking, disbursement documentation, flat-fee split payment, corporate PO fields, and contingency closing statements. InvoiceFlow handles the invoicing structure for all of these from one Android app.

Retainer Replenishment Invoices

For clients maintaining advance retainers, monthly invoices show the retainer balance, billing for the period, and replenishment request:

“Matter Invoice — [Client Name] — [Month Year]: Matter: [Description] — Case/Matter No. [Number] Retainer balance at start of period: $4,200.00 Professional services this period: [Date] — [Task description] — [X.X hours × $385/hour]: $[Amount] [Date] — [Task description] — [X.X hours × $385/hour]: $[Amount] Disbursements: [Description]: $[Amount] Total billed this period: $[Total] Retainer balance after billing: $[Remaining] Replenishment to restore $4,000.00 minimum: $[Amount] Please remit: $[Amount]”

The replenishment amount and remaining balance on every invoice eliminates client confusion about retainer status.

Hourly Matter Invoices

Invoice Flow app invoice editor of a solo attorney — attorney and paralegal hours plus court filing and courier disbursements with matter number and bar number in custom fields — Attorney and paralegal time plus disbursements — one matter invoice, no separate reimbursement request.

For matters billed hourly without a retainer:

“Matter Invoice — [Client Name] — [Month Year]: Matter: [Description] Professional services: [Date] — [Task]: [Hours] hours × $385/hour: $[Amount] [Date] — [Task]: [Hours] hours × $385/hour: $[Amount] Disbursements: Court filing fee: $350.00 [Other cost]: $[Amount] Total professional fees: $[Amount] Total disbursements: $[Amount] Total due: $[Total] Payment Terms: Net-15”

Disbursements separated from professional fees — clients understand specific costs they recognize without dispute.

Flat-Fee Matter Invoices with Split Payment

Estate planning, formation documents, and standard transaction matters on flat-fee:

“Flat-Fee Legal Services — [Client Name] — [Date]: Service: [Service Description] Scope: [List of deliverables included] Flat fee: $2,400.00 Deposit (50%, due at engagement start): $1,200.00 Balance (due upon [milestone — e.g., document execution]): $1,200.00”

The scope definition limits creep. The split payment structure is more palatable to clients than a single upfront payment for flat-fee matters.

Corporate Client Invoices with PO Fields

Business clients with procurement departments require:

“Legal Services — [Company Name] — [Month Year]: Matter: [Description] | Matter Number: [MAT-Year-XXXX] Professional services: [Hours] × $385/hour: $[Amount] Disbursements: $[Amount] PO Number: [PO Number] Billing Contact: [Name, Department] Payment Terms: Net-30”

Corporate clients process invoices faster when they match a PO number. Include both the matter number and the PO number — finance needs the PO, your files need the matter number.

Contingency Closing Statements

Invoice Flow app documents of a law practice — a corporate lease matter, a paid estate-plan retainer, a startup contract review and a paid dispute matter — Matters, retainers, disputes — each with its matter number, no practice-management suite required.

Settlement disbursement statements at matter close:

“Contingency Fee Statement — [Client Name] — [Date]: Matter: [Description] Settlement amount: $85,000.00 Contingency fee ([%] of settlement): $[Amount] Advanced costs (see itemized schedule attached): $[Amount] Net to client: $[Amount] Settlement funds received: [Date] Client disbursement: Within [N] business days of this statement”

Always attach the itemized cost schedule. A closing statement without itemized deductions generates client questions that delay disbursement.

What InvoiceFlow Does for Lawyers

Retainer invoices: balance shown, billing applied, replenishment amount clearly stated
Hourly matter invoices: task-level line items with disbursements separated
Flat-fee split payment: deposit + balance at milestone for estate and formation matters
Corporate PO fields: PO number, matter number, billing contact, net-30 terms
Contingency closing statements: settlement amount, fee, costs, and net-to-client
Payment tracking: see outstanding amounts by client and matter

Getting Started

Build a retainer invoice template with balance, billing, and replenishment fields
Create a hourly matter template with disbursement line items
Set up a flat-fee template with 50% deposit + milestone balance structure
Add corporate custom fields (PO number, matter number) to your corporate client template
Build a contingency closing statement template with settlement math documented

Download InvoiceFlow. Build your matter-level invoice templates. Retainer tracking and corporate PO billing don’t require expensive legal billing software — they require the right invoice structure, which InvoiceFlow provides.

InvoiceFlow is a free invoicing app for Android, designed for independent professionals and small business owners.