Guides
Guides
Practical, plain-language guides on invoicing, getting paid, and running the paperwork side of a small business.
These guides explain the paperwork side of running a small business in plain language. They cover how to write an invoice, how to set payment terms, how to chase late payers and how to keep clean records.
Guides give general information, not legal or tax advice. Rules differ by country, so check the details with your tax authority or an accountant. Pair a guide with the free generators and calculators on this site.
Getting Started
Start here if you are new to invoicing: what to include, how to number documents and how to set terms.
- How to Invoice a Client for the First TimeThe exact steps to send your first invoice, from what to prepare beforehand to what happens after you hit send.
- Invoice vs. Receipt vs. Quote: Which Document Do You Need?Three documents that get mixed up constantly: what each one means, when to send which, and a worked example of all three on one job.
- What to Include on Every InvoiceWhat to put on an invoice: a complete checklist of required fields, from invoice number and dates to tax details and payment terms, plus the ones people forget.
- How to Number Your InvoicesA numbering system that stays consistent as you grow, with worked formats, a setup checklist, and the mistakes that cause the most bookkeeping headaches.
- How to Set Payment Terms and Due DatesWhat 'Net 30' actually means, how to choose terms that fit your business, and why a due date beats a vague deadline every time.
- How to Choose an Invoice TemplateWhat actually matters in an invoice template, a checklist to test one in five minutes, and the handful of things that matter far less than people assume.
- From Estimate to Paid Invoice: The Full WorkflowHow a job actually moves from a rough quote to money in your account, and which document marks each step.
Getting Paid
Reminders, late fees, payment methods and what to do when a customer does not pay.
- How to Get Paid FasterSmall changes to how you invoice that measurably shorten the time between sending an invoice and getting paid.
- How to Reduce Late PaymentsThe patterns behind why invoices go unpaid on time, and the changes that prevent most of them before they happen, with a worked cost example and checklist.
- Accepting Online Payments on an InvoiceWhy a payment link beats bank details in an email, how to add one without building payment infrastructure, and how to weigh the processing fee.
- Invoice Late Fees: Whether and How to Charge OneHow to calculate and charge an invoice late fee: common rates (often 1–5%), how to put it in your payment terms, and when it's smarter to waive it.
- Invoice Follow-Up: When and How to Check InA timeline for following up on an invoice that catches problems early without sounding like a complaint.
- Invoice Reminder TemplatesReady-to-adapt wording for each stage of following up on an invoice, from a friendly nudge to a firmer final notice, with a timeline and common mistakes.
- What to Do When an Invoice Goes OverdueAn overdue invoice is unpaid after its due date. Follow this step-by-step sequence of reminders, calls and final notices to collect it, and know when to stop.
- Collection Letter TemplatesFormal wording for when routine follow-up hasn't worked and an invoice needs a more serious written notice, with a timeline and a pre-send checklist.
- How to Collect on Unpaid InvoicesThe realistic options once follow-up and collection letters haven't worked: what each one costs, and when it's worth it.
- Bad Debt: When to Write Off an Unpaid InvoiceHow to recognize when an invoice is genuinely uncollectible, what writing it off means for your books, and how to measure bad debt over time.
Business Documents
How each business document works, from quotes and receipts to purchase orders and packing slips.
- Estimate vs. Quote: What's the Real Difference?Both give a client a number before work starts, but one is binding and the other explicitly isn't. Here's how to tell which to send.
- Invoice Statuses: Tracking Where Every Invoice StandsA simple set of statuses that makes it obvious, at a glance, which invoices need attention, with a worked tracking example and a weekly review routine.
- Credit Notes: How to Correct an Invoice Without Deleting ItWhat a credit note actually does, when to issue one, and why it's the right fix instead of editing a sent invoice.
- Credit Memo vs. Credit Note: Same Document, Different NameA credit memo and a credit note are the same document: a seller's record that reduces what a customer owes. See the US vs. UK/EU terms, a VAT example and how to issue one.
- Purchase Orders: What They Are and When You'll Use OneA purchase order is the buyer's own authorization to spend. Here is what it means for you as the seller, how to handle one, and when to issue your own.
- Purchase Order vs. Invoice: Who Issues What, and WhenBoth list items and prices, but they come from opposite sides of a transaction, at different points in the process. Here is how they fit together, with an example.
- Sales Order vs. Purchase Order: Two Sides of the Same TransactionA purchase order and a sales order can describe the exact same transaction from opposite sides of the table. Here is how they relate, with a worked example.
- Commercial Invoice: What It Is and When You Need OneA commercial invoice is the customs document for international shipments. See what it must include and how it differs from a regular or proforma invoice.
- Pro Forma Invoice: A Preview, Not a BillWhy a document that looks exactly like an invoice isn't actually a request for payment, when to send one, and how to follow it with the real invoice.
- Work Orders: Authorizing and Tracking a JobThe document that turns a verbal 'go ahead' into something both sides can point back to if there's ever a question, with an example and checklist.
- Packing Slip vs. Delivery Note: What's the Difference?Two documents that both travel with a shipment and list what's inside, close enough in purpose that the names get used interchangeably. Here is when the difference matters.
- Using Timesheets for Client BillingHow to keep time records that hold up when a client questions an hourly invoice, and turn them into one cleanly, with a worked example.
Customer Billing
Recurring invoices, deposits, statements and other ways to bill customers over time.
- Recurring Invoices: Billing the Same Client on a ScheduleHow to handle billing for retainers, subscriptions, and ongoing services without rebuilding an invoice from scratch every time, with a worked schedule.
- Customer Statements: Summarizing an Account, Not a Single SaleWhen one invoice isn't enough: how a statement shows everything a client owes across a period, in one document.
- Invoice Deposits: Getting Paid Before You StartWhen to ask for money upfront, how to invoice for it cleanly, and how to handle the remaining balance once work is done.
- Progress Invoicing: Getting Paid in Stages on Long ProjectsHow to split a large project into milestone invoices, with a worked schedule, so you're not waiting until the very end to see any money.
- Payment Plans: Letting a Client Pay Over TimeWhen it's worth offering installments on a large invoice, and how to structure a plan that actually gets followed, with a worked schedule.
- Retainer Agreements: Getting Paid for Availability, Not Just OutputHow a retainer differs from ordinary project billing, what to put in the agreement, and how to invoice it cleanly, with a worked example.
Business Management
Record keeping, taxes, cash flow and the habits that keep a small business organized.
- Cash Flow Basics: Why Profitable Businesses Still Run Out of MoneyProfit and cash aren't the same thing, and the gap between them is where otherwise healthy small businesses get into trouble.
- Gross Profit vs. Net Profit: Two Very Different NumbersBoth get called 'profit,' but one ignores most of your costs and the other doesn't. Confusing them leads to real pricing mistakes.
- How to Read Financial Statements (Without an Accounting Degree)The three basic statements every small business generates, a worked example of reading them together, and the handful of numbers worth your attention.
- How to Price Your ServicesThree common approaches to setting a price, a worked example of each, and why most sustainable pricing ends up blending more than one of them.
- Accounts Receivable BasicsWhat accounts receivable actually measures, why it deserves attention on its own, and the metrics that turn it from a number into a signal.
- Invoice Aging Reports: Seeing Which Overdue Invoices Need Attention FirstA simple way to sort unpaid invoices by how overdue they are, so the oldest, riskiest ones don't get lost among the merely late.
- Days Sales Outstanding (DSO): What It Measures and Why It MattersA single number that tells you, on average, how long it actually takes to get paid, and why watching its trend matters more than any one reading.
- Accounts Receivable Turnover: A Different Angle on the Same ProblemWhere DSO measures collection speed in days, turnover measures it in cycles. Learn the formula, a worked example, and how to read the result.
- Cash Application: Matching Payments to the Right InvoiceGetting paid is only half the job. Knowing exactly which invoice a payment covers keeps your records accurate and your follow-ups fair.
- Payment Reconciliation: Making Sure Your Records Match RealityA regular habit that catches missing payments, duplicate entries, and small errors before they compound into a real mess, with a worked example.
- Handling Invoice Disputes Without Damaging the RelationshipA client questioning an invoice isn't automatically a problem. How you respond determines whether it stays that way.
- Working Capital: The Cushion That Keeps a Business RunningWhat working capital measures, why unpaid invoices tie it up, and how to keep enough of it to absorb a slow month, with a worked example.
- Revenue Forecasting for Small BusinessesA simple, honest way to estimate what's coming in over the next few months, with a worked three-scenario example, without pretending to more precision than you have.
- Collection Effectiveness Index (CEI): Measuring How Well You CollectA metric that compares what you actually collected against what you could have collected, less distorted by sales swings than DSO.