Invoicing Workflow for Solos: When, How, and What to Do When Clients Don't Pay

Most solos hate invoicing. It feels awkward, you forget to send them, and chasing late payments is uncomfortable.

This guide gives you a system: when to invoice, what tools to use, payment terms that actually work, and scripts for following up when clients don't pay.

Why Your Invoicing System Matters

A good invoicing workflow:

• Gets you paid predictably (protects cash flow)
• Reduces awkwardness (you have a process, not a conversation)
• Builds credibility (you look professional)
• Creates a paper trail (for taxes and disputes)
• Saves time (automation > manual work)

The goal: Get paid on time without being pushy or forgettable.

The Default Invoicing Timeline

Here's the standard workflow for most service-based solo work:

For Project-Based Work (Fixed Price)

Upfront (Before Work Starts):

• 25-50% deposit invoice
• Due: upon contract signature
• Payment before: work begins

Milestone Invoices:

• Tied to deliverables, not time
• Due: upon milestone completion or approval
• Example: 25% on wireframes, 25% on final designs, 50% on launch

Final Invoice:

• Remaining balance
• Due: upon project completion
• Payment before: final files/access transferred

For Retainer Work (Monthly)

Invoice Timing:

• Send on the same day each month (1st, 15th, last day—pick one)
• Invoice for the upcoming month, not the past month
• Example: invoice sent Jan 1 for January work

Payment Terms:

• Due upon receipt or Net 7 (not Net 30—you're not a corporation)
• Auto-renew unless client cancels with notice (define notice period)

For Hourly Work

Invoice Frequency:

• Weekly (for short engagements)
• Biweekly (for ongoing work)
• Monthly (if hours are predictable)

Invoice Timing:

• Send at end of the billing period
• Due: Net 7 or Net 14

Include:

• Hours worked (breakdown by date or task)
• Hourly rate
• Total amount due
• Payment due date

For Product/SaaS (Subscription)

Automation Required:

• Use Stripe, Paddle, or similar
• Auto-charge monthly or annually
• Send receipt after payment (not an invoice)

The Anatomy of a Good Invoice

Required Elements

Every invoice must include:

Your Information:

• Business name (or your name if sole prop)
• Address
• Email
• Phone (optional)
• Tax ID / EIN (if applicable, especially for B2B)

Client Information:

• Client name (individual or company)
• Billing address
• Contact email

Invoice Details:

• Invoice number (sequential: INV-001, INV-002, or date-based: 2025-01-001)
• Invoice date
• Due date (explicit, not "Net 30" alone)
• Description of work or deliverables
• Amount due
• Payment terms

Payment Instructions:

• Accepted methods (ACH, credit card, check, wire)
• Where to send payment (link, bank details, mailing address)
• Late payment policy (if applicable)

Optional But Helpful

• Purchase Order (PO) number (if client requires it)
• Project name or reference number
• Itemized breakdown (especially for hourly work)
• Subtotal, tax (if applicable), total
• Notes or thank you message

What a Good Invoice Looks Like

Example (Project-Based):

INVOICE

From:
[Your Business Name]
[Your Address]
[Your Email]
[Your Phone]

To:
[Client Name / Company]
[Client Address]
[Client Email]

Invoice #: INV-2025-003
Invoice Date: January 15, 2025
Due Date: January 22, 2025 (Net 7)

Description:
Website redesign project - Milestone 2: Design approval
Per SOW dated December 1, 2024

Amount Due: $2,500.00

Payment Methods:
- ACH: [Link to payment portal]
- Credit Card: [Link to payment portal]
- Check: Mail to [Address]

Payment Terms: Net 7 from invoice date
Late Payment: 1.5% monthly interest on overdue balances

Thank you for your business!

Example (Retainer):

INVOICE

From: [Your Name]
To: [Client Name]

Invoice #: INV-2025-004
Invoice Date: February 1, 2025
Due Date: February 8, 2025

Description:
Monthly retainer - February 2025
[X hours / Y deliverables as agreed]

Amount Due: $4,000.00

Payment due upon receipt. Auto-renews monthly unless canceled with 30 days notice.

Pay via: [Link]

Example (Hourly):

INVOICE

From: [Your Name]
To: [Client Name]

Invoice #: INV-2025-005
Invoice Date: January 31, 2025
Due Date: February 7, 2025

Description:
Consulting services - January 16-31, 2025

Breakdown:
- Jan 16: Strategy session (3 hours) - $450
- Jan 18: Implementation work (5 hours) - $750
- Jan 23: Client review call (1.5 hours) - $225
- Jan 25: Documentation (4 hours) - $600

Total Hours: 13.5
Hourly Rate: $150
Amount Due: $2,025.00

Payment due within 7 days.
Pay via: [Link]

Payment Terms That Work

Standard Terms for Solos

Net 7: Payment due within 7 days

• Best for: most solo work
• Why: fast payment, reasonable for clients

Net 14: Payment due within 14 days

• Best for: larger invoices, corporate clients
• Why: gives client time for internal approvals

Net 30: Payment due within 30 days

• Best for: avoid if possible (kills your cash flow)
• Use only if: client requires it (enterprise clients)

Upon Receipt: Payment due immediately

• Best for: deposits, final invoices, small amounts
• Why: clear expectation, no confusion

Recommendation for solos: Default to Net 7 for most work. Use upon receipt for deposits.

Payment Terms to Include in Contracts

Don't rely on the invoice alone. Payment terms should be in your contract/SOW:

In Your Contract:

• Invoice schedule (when you'll invoice)
• Payment terms (Net 7, Net 14, etc.)
• Accepted payment methods
• Late payment policy (interest rate, suspension of work)
• What happens on non-payment (termination rights, collections)

See: Contract Basics for Solos for template language.

Late Payment Policies

Option 1: Interest on Late Payments

• Charge 1.5% monthly interest on overdue balances
• Must be stated in contract and on invoice
• Legal in most jurisdictions (check local laws)

Option 2: Pause Work

• Stop work if payment is [X] days late
• Resume when account is current
• Must be in contract

Option 3: Collections

• Send to collections after [X] days (60-90 typical)
• Use a collections agency or small claims court
• Last resort (damages relationship)

Recommended approach:

• Net 7 terms
• Pause work at 14 days overdue
• Collections at 60 days overdue (if necessary)

Invoicing Tools (What to Use)

Option 1: Invoicing Software (Recommended)

Wave (Free)

• Best for: simple invoicing needs
• Pros: free, clean UI, tracks paid/unpaid
• Cons: limited automation, no advanced features
• Cost: Free (charges for payment processing)

FreshBooks ($19-60/month)

• Best for: service-based solos
• Pros: invoicing + time tracking + expenses
• Cons: overkill if you only need invoicing
• Cost: $19/month (lite), $33/month (plus)

QuickBooks Online ($30-60/month)

• Best for: full bookkeeping + invoicing
• Pros: industry standard, robust features
• Cons: clunky UI, steep learning curve
• Cost: $30/month (simple start)

Stripe Invoicing (Free, $$ on payments)

• Best for: online payments, recurring billing
• Pros: clean, simple, great for subscriptions
• Cons: limited customization
• Cost: Free to send, 2.9% + $0.30 per transaction

Recommendation:

• Start with Wave (free, simple)
• Upgrade to FreshBooks if you need time tracking
• Use Stripe Invoicing if you do subscriptions or want fast online payments

Option 2: Manual (Google Docs / Excel)

When it works:

• You send 1-5 invoices/month
• You don't need automation or tracking
• You're comfortable with manual follow-up

How to do it:

• Create a template in Google Docs or Excel
• Save a copy for each invoice
• Export as PDF and email
• Track paid/unpaid in a spreadsheet

Pros: Free, full control Cons: Time-consuming, no automation, easy to forget

Recommendation: Only use this if you're sending very few invoices. Upgrade to software as soon as it becomes a pain point.

Option 3: Payment Links (Stripe, PayPal, Square)

When it works:

• Quick one-off payments
• Informal arrangements
• Deposits before full contract

How to do it:

• Create a payment link via Stripe, PayPal, or Square
• Send link to client
• They pay instantly

Pros: Fast, easy, low friction Cons: Not a formal invoice (may not satisfy accounting/tax needs)

Use case: Good for deposits or quick payments. Not a replacement for proper invoicing.

How to Send Invoices

Best Practices

1. Send via Email (Default)

• Attach PDF invoice
• Include payment link in email body
• Use clear subject line: "Invoice INV-2025-003 - Due Jan 22"

Example Email:

Subject: Invoice INV-2025-003 - Due January 22

Hi [Client Name],

Attached is your invoice for [project/retainer/work period].

Invoice #: INV-2025-003
Amount Due: $2,500
Due Date: January 22, 2025

Pay via: [Payment Link]

Let me know if you have any questions.

Thanks,
[Your Name]

2. Use Invoicing Tool's Built-In Sending

• Most tools (Wave, FreshBooks, Stripe) let you send directly
• Includes payment link automatically
• Tracks views and payments
• Sends reminders

3. Include a Payment Link (Always)

• Don't make them ask how to pay
• Stripe, PayPal, ACH link in the email body and on the invoice
• Reduces friction = faster payment

4. Be Consistent

• Invoice on the same schedule every time
• Use the same format and template
• Train clients to expect invoices on a specific day

When Clients Don't Pay (The Follow-Up System)

The Default Follow-Up Timeline

Day 0: Invoice sent, due in 7 days

Day 7 (Due Date):

• If paid: send thank you (optional but nice)
• If unpaid: wait 1-2 days (sometimes they're just slow)

Day 8-9 (1-2 Days Overdue):

• Send friendly reminder (assume good intent)

Day 14 (7 Days Overdue):

• Send firmer reminder
• Pause work if in contract

Day 21 (14 Days Overdue):

• Send final notice before escalation
• Explicitly state consequences (work paused, collections, etc.)

Day 30-60 (If Still Unpaid):

• Consider collections agency or small claims court
• Evaluate whether relationship is worth salvaging

Follow-Up Email Scripts

Reminder 1 (Day 8-9, Friendly):

Subject: Friendly reminder: Invoice INV-2025-003 due Jan 22

Hi [Client Name],

Just a quick reminder that Invoice INV-2025-003 for $2,500 was due on January 22.

I know things get busy—if you've already sent payment, please disregard this email.

If not, you can pay here: [Link]

Let me know if you have any questions or need a copy of the invoice.

Thanks,
[Your Name]

Reminder 2 (Day 14, Firmer):

Subject: Invoice INV-2025-003 now 7 days overdue

Hi [Client Name],

Invoice INV-2025-003 for $2,500 is now 7 days past due (originally due January 22).

Per our agreement, I'll need to pause work on [project] until the account is current.

Please let me know if there's an issue with the invoice or if you need to discuss payment terms.

You can pay here: [Link]

Thanks,
[Your Name]

Final Notice (Day 21):

Subject: Final notice: Invoice INV-2025-003 now 14 days overdue

Hi [Client Name],

This is a final notice that Invoice INV-2025-003 for $2,500 is now 14 days past due.

If payment is not received by [Date - usually 7 days out], I will need to [send to collections / pursue legal action / other consequence per contract].

If there's a payment issue or dispute, please reach out immediately so we can resolve it.

Payment link: [Link]

[Your Name]

What to Do If They Still Don't Pay

Option 1: Negotiate a Payment Plan

• Offer to split into 2-3 installments
• Better to get paid slowly than not at all
• Get agreement in writing

Option 2: Small Claims Court

• For amounts under $5,000-$10,000 (varies by jurisdiction)
• You don't need a lawyer
• Costs $50-$200 to file
• Takes time but often works

Option 3: Collections Agency

• They take 25-50% of what they collect
• Damages relationship permanently
• Only use if relationship is already dead

Option 4: Write It Off

• Sometimes it's not worth the hassle
• Deduct as a bad debt on taxes (consult CPA)
• Learn from it: tighten payment terms, require deposits, vet clients better

How to Prevent Late Payments

Strategy 1: Require Deposits

For project work:

• 25-50% upfront before work starts
• Remaining balance on milestones or completion

Why it works:

• Demonstrates commitment
• Reduces your risk
• Clients who won't pay a deposit often won't pay at all

Strategy 2: Use Shorter Payment Terms

Default to Net 7, not Net 30

• Net 30 is for corporations with accounting departments
• Solos need fast cash flow
• Net 7 is reasonable and standard for small vendors

Strategy 3: Invoice on Milestones, Not at the End

Break large projects into milestones:

• Invoice 1: Deposit (25%)
• Invoice 2: Milestone 1 complete (25%)
• Invoice 3: Milestone 2 complete (25%)
• Invoice 4: Final delivery (25%)

Why it works:

• Smaller amounts are easier to pay
• You're not carrying all the risk
• Cash flow stays healthy

Strategy 4: Pause Work on Late Payments

In your contract: "If payment is more than [7/14] days overdue, work will be paused until the account is current."

In practice:

• Send a polite email at the pause threshold
• Actually stop working (don't bluff)
• Resume when paid

Why it works:

• Creates urgency
• Protects you from working for free
• Signals you're serious about payment

Strategy 5: Make Payment Easy

Reduce friction:

• Accept multiple payment methods (ACH, credit card, PayPal)
• Include payment link in invoice email
• Use invoicing software with one-click payment
• Don't make them ask "how do I pay this?"

Why it works:

• Clients delay when payment is hard
• Easy payment = faster payment

Strategy 6: Vet Clients Before Signing

Red flags:

• Pushback on deposits
• Vague about budget or payment terms
• Ask for Net 60 or Net 90
• Complain about past vendors constantly

Green flags:

• Pay deposit promptly
• Ask clear questions about invoicing
• Have an established business
• References check out

Invoicing for Different Work Types

Retainer Clients

Best practice:

• Invoice on the 1st of each month for that month's work
• Use auto-billing if possible (Stripe, PayPal subscriptions)
• Net 7 payment terms
• Auto-renew unless canceled with 30 days notice

Include in contract:

• Monthly retainer amount
• What's included (hours, deliverables, meetings)
• Overage policy (if applicable)
• Cancellation terms

Project-Based Work

Best practice:

• 25-50% deposit upfront
• Remaining balance split across milestones
• Final invoice before final delivery/handoff

Include in contract:

• Payment schedule tied to deliverables
• What triggers each invoice (milestone approval, date)
• Final payment required before final files/access

Hourly Consulting

Best practice:

• Invoice weekly or biweekly
• Include timesheet or breakdown
• Net 7 payment terms
• Cap hours per period (to avoid surprise bills)

Include in contract:

• Hourly rate
• Invoicing frequency
• Payment terms
• How hours are tracked and reported

Productized Services (Fixed Deliverable)

Best practice:

• 50% deposit upfront
• 50% on delivery
• Clear scope to avoid scope creep

Include in contract:

• What's included in fixed price
• What's out of scope
• Revision policy
• Timeline

Integration with Your Broader Operations

Invoicing connects to your full operations system:

Before Invoicing:

• Contract signed (payment terms defined)
• Work scoped (clear deliverables)
• Onboarding completed (client expectations set)

See: Contract Basics for Solos and Client Onboarding as a Solo.

During the Project:

• Track time or milestones
• Invoice on schedule
• Monitor payment status
• Follow up on late payments

After Payment:

• Reconcile with bookkeeping
• Save invoices for taxes
• Track client payment patterns

See: Solo Finance Setup for bookkeeping integration.

When to Upgrade Your Invoicing System

Start Here (Minimum Viable):

• Google Docs template or Wave (free)
• Manual sending via email
• Manual follow-up on late payments
• Spreadsheet to track paid/unpaid

Upgrade When You're Sending 10+ Invoices/Month:

• Switch to invoicing software (Wave, FreshBooks, QuickBooks)
• Use built-in payment links
• Set up automated reminders

Upgrade When You're Sending 25+ Invoices/Month:

• Integrate invoicing with bookkeeping (QuickBooks)
• Use recurring billing for retainers (Stripe, PayPal subscriptions)
• Automate as much as possible (reminders, receipts, follow-ups)
• Consider a VA to handle invoicing workflow

The Bottom Line

A good invoicing system:

• Clear terms: Net 7, payment link included
• Consistent timing: Invoice on the same day every time
• Easy payment: Multiple methods, one-click links
• Proactive follow-up: Friendly reminder at 1-2 days late, firmer at 7 days

Start simple:

1. Use Wave or a Google Docs template
2. Invoice on a consistent schedule
3. Include payment links
4. Follow up politely but firmly on late payments

The system compounds:

• Clients learn your rhythm
• Payment becomes routine
• You get paid predictably

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Next Steps

Build out your operations system:

• Client Onboarding as a Solo - Complete onboarding process
• Intake Forms That Work - Template and best practices
• Scoping Projects to Prevent Scope Creep - Define deliverables

Set up the legal and financial foundation:

• Contract Basics for Solos - Payment terms in contracts
• Solo Finance Setup - Banking, bookkeeping, cash flow

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