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Invoicing and estimating guides
What to quote, what to put on an invoice, how to get it paid, and what the rules actually say.
How to invoice
Writing, sending and getting paid for an invoice.
- How to ask a client for a deposit Choosing an amount, wording the request, and invoicing it so the final balance still adds up.
- How to charge late fees on an invoice Wording a late fee so it is collectable, choosing a rate, and deciding when to actually apply it.
- How to follow up on an unpaid invoice A reminder schedule, the wording for each stage, and the point at which chasing stops working.
- How to invoice an international client Currency, bank details and transfer fees — getting a cross-border invoice paid in full.
- How to invoice as a freelancer What to bill for, how to word it, and how to stop being the supplier who gets paid last.
- How to invoice for hourly work Detail, rounding and unexpected hours — billing time without inviting a line-by-line argument.
- How to send an invoice by email Subject lines, recipients and attachments — the email that gets an invoice into the payment run.
- How to write an invoice The nine things every invoice needs, why each one is there, and how to send it so it gets paid on time.
- Invoice numbering systems Sequential, dated and per-client numbering compared, and the mistakes that only show up a year later.
- Invoice payment terms explained Net 30, due on receipt, EOM and early-payment discounts — what each means and when to use it.
- Invoice vs receipt One asks for money, the other confirms it arrived — and each carries different information.
- What is a proforma invoice? A commitment to price rather than a demand for payment — when to send one and what to put on it.
- What is an invoice? A written claim for money that is already owed — issued by the seller, before the payment, and never the same thing as a receipt.
US rules and practice
What US law and practice expect of the document and your records.
- 1099-NEC vs W-9 One collects a contractor's details, the other reports what was paid — and different people file them.
- Does an invoice need a tax ID number? When a US invoice needs an EIN, when it does not, and why an SSN does not belong on one.
- How long to keep invoices The period of limitations, the situations that extend it, and what form records should be kept in.
- Late payment rules by state Which state rules govern late fees and prompt payment, and which ones apply to your work.
- Sales tax on services Whether a service is taxable depends on the state and the service — how to find your own answer.
- What makes an invoice legally valid? No federal format exists — what matters is what the document evidences, and what you kept with it.
Estimates and quotes
Pricing the job, sending the offer, and turning a yes into an invoice.
- Change orders: when the job grows Extra work priced on the invoice is a surprise. Priced when it appears, it is a decision.
- Estimate vs quote: what is the difference? One is a considered price that may move; the other is an offer at a fixed price. How to tell which you are sending.
- How long should an estimate be valid? Pick the period from what drives your cost, not from the round number everyone copies.
- How to follow up on an estimate When to chase, what to write, and why an easy no is worth more than silence.
- How to turn an estimate into an invoice What carries over, what must not change quietly, and why the estimate stays in the record.
- How to write an estimate The anatomy of an estimate, and how to word the parts of a job you cannot price exactly yet.
- Is an estimate legally binding? Usually not, and the wording is what decides. What moves an estimate toward being an offer.
- Markup vs margin A 50% markup is a 33% margin. Confusing the two underprices every job, quietly.
Put any of it into practice
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