Secure Billing · Client-Side Privacy

Sign Invoices & Billing Online

Need to authorize an invoice, purchase order, or billing statement? Add your electronic signature, "PAID" stamp, or company seal to your financial documents instantly.

  • Financials Kept Private
  • No Server Uploads
  • ESIGN Compliant
  • No Account Required
1
Create Signature
2
Sign Document

Authorize Invoice

Create your signature or upload a company stamp. Once adopted, upload your billing PDF.

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100% Secure

Everything runs in your browser. Your documents never touch a server.

Legally Binding

Signatures meet standard digital signature requirements for common agreements.

How to Sign Your Invoice for Payment

1

Create Signature

Type your name, draw a signature, or upload a company seal PNG.

2

Load Invoice

Drop your invoice PDF securely into the browser workspace.

3

Apply Authorization

Position your signature or stamp on the document. Add payment dates if necessary.

4

Export Document

Download the finalized file and send it to Accounts Payable.

Invoice Essentials: The 9 Mandatory Elements and How to Handle Disputes

An invoice is not just a bill — it is a legal document that establishes a payment obligation. Before you sign invoice online and send it to your client, understanding what makes an invoice legally sound — and how to protect yourself when one is disputed — can make the difference between getting paid on time and chasing late payments for months.

Invoice vs. Receipt vs. Purchase Order: What's the Difference?

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Purchase Order (PO)

Sent by the buyer before delivery

A PO is generated by the client’s procurement department and sent to the vendor to authorize a purchase. It defines what they want, in what quantity, and at what price. It is not a payment request.

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Invoice

Sent by the vendor after delivery

An invoice is your formal request for payment after delivering goods or completing a service. It should reference the PO number (if applicable) and list everything delivered.

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Receipt

Issued after payment is received

A receipt confirms that payment was received. It is issued by the seller and serves as proof of transaction for the buyer’s accounting records.

9 Mandatory Elements of a Legally Valid Invoice

A missing field can delay payment, trigger compliance issues, or invalidate the document for tax purposes. Make sure every invoice you send includes:

01Invoice Number (unique, sequential)
02Invoice Date (date of issue)
03Payment Due Date (or Net Terms)
04Your business name, address, and contact info
05Client name and billing address
06Itemized list of goods or services rendered
07Unit prices, quantities, and line totals
08Total amount due (with applicable tax)
09Payment instructions (bank wire, ACH, check, etc.)

Net Payment Terms: What to Use for Your Industry

The net payment terms you use should reflect both your cash flow needs and your industry norms:

Due on Receipt

Freelancers, solo consultants, small one-off projects

Net 15

Agencies, small businesses, regular recurring clients

Net 30

Standard B2B commercial terms, most industries

Net 45

Government contractors, healthcare, construction

Net 60

Enterprise clients, large corporations, international

How to Handle a Disputed Invoice

When a client disputes an invoice, respond in writing within 24 hours. Acknowledge their objection, reference your signed contract and the specific deliverables listed in the scope of work, and attach any delivery confirmation emails or client approval messages. If only part of the invoice is disputed, consider issuing a revised invoice for the undisputed portion immediately to receive partial payment while resolving the remainder.

For persistent non-payers, your options escalate as follows: (1) formal demand letter referencing your contract and late fee clause; (2) small claims court for amounts under your state's limit (typically $5,000–$15,000); (3) engaging a collections agency (typically 25–33% commission); (4) hiring a business attorney for amounts warranting litigation.

Why Invoice Privacy Matters

Your invoices reveal your business rates, your client relationships, your revenue, and your payment terms — information you would not want competitors or unauthorized parties to access. Uploading invoices to a cloud PDF signing service means this sensitive business intelligence resides on a third-party server. MyDigitSign signs your invoices entirely within your browser's local memory. Your rates, client names, and revenue figures never leave your device — giving you professional invoice signing with complete financial privacy.

Frequently Asked Questions

What is the difference between an invoice and a receipt?

An invoice is a request for payment sent before payment is received — it details what was delivered, the amount owed, and payment terms (due date, net terms). A receipt is proof that payment was made and is issued after the fact. Signed invoices are important for businesses because they document the payment obligation and create a paper trail for accounting and tax purposes.

What elements are legally required on a business invoice?

A legally valid business invoice should include: (1) the invoice number, (2) invoice date, (3) due date, (4) your business name and address, (5) client's name and address, (6) an itemized list of goods or services, (7) unit prices and quantities, (8) total amount due, and (9) payment method instructions. For EU/UK businesses, VAT registration numbers are also required.

How do I handle a client who disputes my invoice?

Document every dispute in writing immediately. Send a formal written response acknowledging their objection, referencing your signed contract and the specific deliverables listed in your scope of work. If partial payment is disputed, consider issuing a revised invoice for the undisputed portion to receive some payment while resolving the remainder. Consult your contract's dispute resolution clause for next steps.

What does Net 30 mean on an invoice?

Net 30 means the client has 30 calendar days from the invoice date to make full payment. Net 15, Net 45, and Net 60 follow the same convention. For maximum cash flow protection, freelancers and small businesses should negotiate Net 15 or immediate payment (Due on Receipt) whenever possible.

Does an invoice need to be signed to be legally valid?

In most jurisdictions, an unsigned invoice is still a valid payment request. However, adding your signature to an invoice makes it more professional, signals your personal accountability, and makes disputes less likely since both parties have acknowledged the terms. For larger B2B transactions, signed invoices are the standard.

Can I use this to sign invoices created in Excel or Word?

Yes — export your invoice from Excel, Word, or any accounting software as a PDF, then upload it to MyDigitSign to add your signature. The signed PDF can be emailed directly to your client.

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