If you send invoices often, adding a signature should feel like the last step of the job, not a new software project. That is the point of the new signed-in feature in Free Invoice Kit: logged-in users can draw or upload one default signature, save it to the account, and keep the invoice PDF frozen after it is created.
The signature feature is account-only. Guests can still create invoices, but only signed-in users can save a reusable signature and attach it to invoice PDFs. If you want to see the product page first, open the invoice generator with signature page and then come back here for the practical steps.
What the feature does
Free Invoice Kit gives logged-in users one default signature. You can draw it in a canvas popup or upload a signature image from your device. Once it is saved, the builder can place that signature at the bottom of an invoice PDF without changing your normal invoicing flow.
How to add the signature
The builder keeps the steps short. Open the invoice builder, sign in, and look for the signature block on the right side of the desktop layout or near the end of the mobile layout. From there you can draw a signature, upload one, name it, and save it as the default for your account.
Why one default signature is enough
Most people only need one signature style for invoices. Keeping one default avoids the clutter of multiple saved versions and makes the builder easier to use on a phone. If you want to change it later, you can redraw it or upload a new image and replace the old default.
Why the invoice keeps a frozen snapshot
This is the part that protects your history. When an invoice is saved with a signature attached, the PDF uses the exact version that was present at that moment. If you update your default signature later, older invoices stay the same. That matters when you need a sent invoice to remain consistent for records, clients, or follow-up.
New signature, new invoices. Old invoices stay as they were.
When upload is better than drawing
Draw it if you want something quick and you are already on the device where you create invoices. Upload it if you already have a clean signature file or you prefer a more controlled result. Both paths lead to the same outcome: one saved default signature that can be reused on future invoices.
Quick checklist before you send
- Confirm that you are signed in before you try to save the signature.
- Make sure the signature looks clear at normal PDF size.
- Check the invoice totals and client details before generating the file.
- Remember that older invoices keep their original signature snapshot.
What to do next
If you want a signed invoice PDF, open the feature page, then go to the builder and save your first default signature. If you usually send invoices in chat, the WhatsApp workflow guide shows how to move the finished PDF into the conversation quickly.