Sign & Approve Invoices — PDF Signature in Seconds

In many businesses, invoices require a manager's signature before they can be processed for payment. This approval step confirms that the goods or services were received, the amount is correct, and the payment is authorized. Traditionally, this meant printing the invoice, signing it with a pen, scanning it, and filing the paper copy. That workflow is slow, wasteful, and creates bottlenecks when the approver is traveling or working remotely.

With SigPDF, invoice approval takes seconds instead of hours. Open the invoice PDF, add your signature, and download the approved document. The signed invoice can be emailed to accounts payable, attached to a purchase order, or filed digitally — all without touching a printer or scanner.

Common Invoice Signing Scenarios

• Approval signatures — Managers and department heads sign invoices to authorize payment. This is the most common use case for invoice signatures.
• Freelancer and contractor invoices — Some clients require that freelancers sign their own invoices to certify the accuracy of billed hours or deliverables.
• Receipt confirmation — A signed invoice can serve as confirmation that goods were delivered and accepted, providing a paper trail for both buyer and seller.
• Vendor onboarding — New vendor agreements sometimes require signed proforma invoices before a purchase order is issued.
• Audit and compliance — Having signed invoices on file provides clear documentation for internal audits, external audits, and tax compliance reviews.

Streamline Your Business Workflow

Invoice approval bottlenecks cost businesses real money. When an invoice sits unsigned on a desk for days, you risk late-payment penalties, strained vendor relationships, and missed early-payment discounts. SigPDF removes the bottleneck by making it possible to sign invoices from anywhere — on a desktop at the office, on a laptop at home, or on a phone while traveling.

A typical workflow with SigPDF looks like this:

1. The invoice arrives by email as a PDF attachment
2. The approver opens SigPDF and loads the invoice
3. They draw or place their approval signature on the document
4. The signed PDF is downloaded and forwarded to accounts payable
5. Payment is processed without delays

The entire process takes under a minute. No software installation, no login to a third-party platform, and no waiting for document processing on a remote server.

Keep Financial Documents Private

Invoices contain sensitive financial information — line-item pricing, payment terms, bank account details for wire transfers, tax identification numbers, and client billing addresses. Uploading these documents to a cloud-based signing platform means trusting a third party with your financial data.

SigPDF processes everything in your browser. Your invoice PDF never leaves your device. There is no server-side processing, no data retention, and no risk of your financial information being exposed in a data breach on someone else's infrastructure.

Add More Than Just a Signature

Beyond your approval signature, SigPDF lets you add text fields and dates to the invoice. This is useful for adding an approval date, a purchase order number, a cost-center code, or a brief note like “Approved for payment” next to your signature. You can also add initials to individual line items if your approval process requires item-level sign-off.

Simple, Flat Pricing

SigPDF costs €2.99/month with unlimited signatures. There are no per-document charges, no tiered plans, and no hidden fees. For businesses that process dozens or hundreds of invoices each month, this flat pricing is significantly more affordable than per-envelope platforms like DocuSign or Adobe Sign.

Legal Validity

Electronic signatures on invoices are legally recognized under the ESIGN Act (United States), eIDAS Regulation (European Union), and equivalent legislation in the UK, Canada, and Australia. A signed invoice carries the same legal weight as one signed with pen and ink, making it fully valid for accounting, tax, and audit purposes.