How to Use GoWin's Free Invoice Generator — Complete Guide

Before you start: what this tool actually does

GoWin's Invoice Generator runs entirely in your browser. There is no account, no subscription, and nothing stored on any server — your invoice data lives only in your browser session. When you click Download PDF, a fully formatted invoice is generated client-side and saved straight to your device. Close the tab and the data is gone, so download before you leave.

The tool is designed for freelancers, small business owners, and sole traders who need clean, professional invoices without the overhead of accounting software. You can have a ready-to-send PDF in under two minutes.

Step 1 — Set up your company profile

The first thing to do is fill in your company profile. Click the Company Profile button at the top of the page. A modal will open with fields for:

• Company name — your trading name or registered business name
• Your name — the contact name that appears on the invoice
• Email address — where clients should reply or raise queries
• Phone number — optional, but adds a professional touch
• Address — your business address (street, city, postcode, country)
• Tax / VAT / GST number — if you are registered, this is legally required on tax invoices in many jurisdictions

Your profile is saved across the session, so it pre-fills every invoice you create during that visit. If you use the tool regularly on the same device, consider keeping a browser bookmark with the profile already in the URL — or simply re-enter it each time (it only takes 30 seconds).

Practical tip: If your business name and trading name differ, use the trading name in the Company Name field — that is what your client recognises. Put the registered legal name in the Notes field at the bottom if it is required by your jurisdiction.

Step 2 — Fill in the invoice header

Once your profile is saved, the main invoice form shows your details at the top. Next, fill in the invoice-level fields:

• Invoice number — use a sequential number (e.g. INV-001, INV-002). Do not reuse numbers. Tax authorities treat invoice numbers as an audit trail, and gaps or duplicates can cause problems during an inspection.
• Invoice date — the date you are issuing the invoice. This is the date from which payment terms are counted.
• Due date — when payment is expected. Common terms are Net 7, Net 14, or Net 30 (payment within 7, 14, or 30 days of the invoice date). For new clients, shorter terms are safer.
• P/O number — if your client issued a Purchase Order, enter its reference here. Many corporate clients require this to match their internal approval workflow, and invoices without a matching P/O number can be held up in accounts payable for weeks.

Step 3 — Enter client details

The Bill To section is where you enter your client's information:

• Client / company name
• Contact name — address it to the specific person who will approve payment, not just the company
• Client email
• Client address — required for formal invoices and for any jurisdiction where VAT or GST applies

Practical tip: Always double-check the client's legal entity name. If they are a limited company, use the full registered name (e.g. "Acme Solutions Ltd" not "Acme"). Mismatches can delay payment because accounts payable teams match the invoice recipient name against their internal vendor records.

Step 4 — Add line items

This is the core of the invoice. Each line item represents one product or service. Click Add Item to add a row. For each item, fill in:

• Description — be specific. "Website development" is vague; "Homepage design and development, per scope agreed 12 March 2025" is better. Clear descriptions prevent disputes.
• Quantity — number of units, hours, days, or licences
• Unit price — the price per unit in your currency
• Amount — calculated automatically (quantity × unit price)

You can add as many line items as you need. If you want to group related items (e.g. design work vs. development work), order them logically — clients read invoices top to bottom and appreciate a clear structure.

Practical tip: If you charge a day rate, set quantity to the number of days and unit price to your day rate. If you charge a fixed project fee, set quantity to 1 and unit price to the full fee. Both approaches produce a clean, unambiguous line item.

Step 5 — Apply tax (GST, VAT, or sales tax)

The tax field lets you add a percentage tax rate to the subtotal. Enter the rate as a number (e.g. 10 for 10% GST in Australia, 20 for 20% VAT in the UK, or 0 if you are not registered or the transaction is zero-rated).

The tool calculates the tax amount and adds it to the subtotal to produce the final total. The breakdown (subtotal, tax amount, total) appears clearly in the summary section and on the PDF.

Important: Only add tax if you are registered to collect it in your jurisdiction. Charging VAT or GST when you are not registered is illegal in most countries. If you are unsure, check with your local tax authority or accountant before adding any tax line.

If you operate across multiple jurisdictions with different rates (e.g. you invoice clients in different countries), GoWin's tool lets you set the rate per invoice — so you can invoice a UK client at 20% VAT and an Australian client at 10% GST without any configuration changes.

Step 6 — Add notes and payment terms

The Notes field at the bottom of the invoice is where you add payment instructions and any additional terms. This is prime real estate — clients read it, especially when they want to know how to pay.

Good things to include in the notes:

• Bank transfer details — account name, BSB/sort code, account number, SWIFT/IBAN for international clients
• Payment methods accepted — bank transfer, PayPal, Stripe link, cheque
• Late payment terms — e.g. "Invoices unpaid after 30 days accrue interest at 5% per annum" (check local laws — many jurisdictions give you a statutory right to charge interest on late payments)
• Project reference or PO reference — if not already in the header
• Thank you note — optional, but a simple "Thank you for your business" goes a long way

Practical tip: Put your bank account details in the notes on every single invoice. Clients should never have to search an old email to find out how to pay you. Making it frictionless to pay is one of the simplest things you can do to get paid faster.

Step 7 — Preview and download the PDF

Once all fields are complete, click Download PDF. The PDF is generated in your browser and saved to your device. Open it and review it before sending — check:

• Your company name and contact details are correct
• The client name and address are correct
• All line items, quantities, and prices are accurate
• The invoice number and date are correct
• Tax has been applied (or not applied) correctly
• Bank details and notes are in the notes section
• The total matches what you agreed with the client

Sending a corrected invoice after the fact is awkward and can delay payment. Spend 60 seconds reviewing the PDF before you hit send.

Step 8 — What to do after downloading

Once you have the PDF, there are a few things to do:

• Save a copy for your records. Even though the tool does not store your invoices, you need to keep copies for tax purposes. Most jurisdictions require you to retain invoice records for 5–7 years. Create a folder structure like Invoices/2025/ClientName/ and save the PDF there.
• Send it promptly. Invoice immediately upon completing work or at the agreed billing date. Delays in sending invoices lead directly to delays in being paid.
• Follow up. If payment has not arrived by the due date, send a polite payment reminder the same day. Most late payments are administrative oversights, not deliberate non-payment. A brief, professional email ("I notice invoice INV-042 for $1,200 was due on 1 April — please let me know if you need anything from my end") resolves the majority of late payments within 24 hours.
• Log it in a simple spreadsheet. Track invoice number, client, amount, date sent, due date, and date paid. This takes five minutes and gives you a clear view of outstanding receivables.

Frequently asked questions

Is the invoice generator really free?

Yes, completely free. No subscription, no free trial, no watermark on the PDF. GoWin Tools is a free browser-based toolkit — no login required and no data leaves your browser.

Can I customise the invoice design?

The current version produces a clean, professional invoice in a standard format that is accepted across all major jurisdictions. Logo and colour customisation are not currently supported — the design is intentionally minimal so it looks professional without requiring design work on your part.

Is this invoice legally valid?

The invoice contains all fields required by most jurisdictions: your business details, client details, itemised services, tax breakdown, and totals. Whether any specific invoice is legally compliant depends on your jurisdiction's requirements — if in doubt, consult your accountant. GoWin Tools does not provide legal or tax advice.

What currency does it support?

You can invoice in any currency. The tool does not enforce a currency — enter prices in whatever currency applies to the transaction and note the currency in the description or notes field.

Ready to create your first invoice?

The whole process — from entering your company details to downloading a PDF — takes about two minutes once you have your line items ready. No account, no payment, no catch.