E-Invoicing in the US: What It Is and How It Works
E-invoicing explained in one minute
An e-invoice is a data file, not a picture of an invoice. It carries the same information as a paper invoice – your business name and EIN, the customer, line items, amounts in USD, due date – but in a structured format such as XML that accounting software reads without anyone retyping it.
A PDF is not an e-invoice
A PDF sent by email is a digital invoice, but it is made for people. Someone still opens it and keys the numbers into their system. An e-invoice skips that step: the data flows straight from your software into your customer's.
E-invoice vs. PDF in one line
PDF = readable by people. E-invoice = readable by software. Both are legal in the US; only the second one is automated.
How e-invoicing works: step by step
You create the invoice in your invoicing software as usual.
The software converts it into a structured format, for example UBL XML or an X12 EDI message.
The file is delivered directly to the customer's system, through their supplier portal, or via an exchange network.
The customer's software validates it (required fields, totals, matching purchase order) and routes it for approval.
Both sides archive the file and the delivery confirmation for their records.
Formats used in the US
There is no national format. In practice you will meet three:
PDF by email – still the most common invoice between small businesses.
X12 EDI (transaction set 810) – used for decades by large retailers, manufacturers and distributors; usually set up per trading partner.
UBL (XML) – the format of the DBNAlliance exchange network, launched in 2023 with support from the Federal Reserve. It uses a four-corner model: you send through your service provider, the customer receives through theirs, so neither side needs the same software.
What the four-corner model means for you
You connect once to a certified service provider (access point). The network finds your customer's provider and delivers the invoice. No separate setup for each customer.
What the law requires
US law regulates the record, not the format:
Electronic invoices are legally valid. Under the federal ESIGN Act, a record cannot be denied legal effect solely because it is electronic.
The IRS accepts electronic records as long as your system can index, retrieve and reproduce them in legible form and protect them from alteration.
Retention: keep invoices and supporting records at least 3 years after filing the return. Keep them 6 years if you underreported income by more than 25%, 7 years if you claim a bad-debt deduction, and 4 years for employment tax records. If you never filed a return, keep them indefinitely.
Customer agreement: between businesses there is no statutory consent rule. Agree on the format and delivery channel with your customer. ESIGN's consent requirements protect consumers specifically.
Practical steps are covered in our guide to archiving and storing invoices digitally.
When is e-invoicing mandatory?
B2B: never, under federal or state law. There is no clearance platform, and invoices are not reported to the IRS in real time.
B2G, federal: since 2015 (OMB Memorandum M-15-19), federal agencies have moved to electronic invoicing for most procurements. If you sell to a federal agency, you submit invoices through its electronic platform.
B2G, state and local: no state-wide mandate; individual agencies may run their own portals.
Large customers: many require a supplier portal or EDI as a contract condition. That is a commercial requirement, not a legal one.
Benefits and risks
Benefits:
Faster approval and payment: no retyping, fewer disputes over typos.
Automatic matching to purchase orders.
A clean audit trail for the IRS.
Risks:
Setup costs and provider fees for EDI or network access.
Rejected invoices when a required field is missing. Check the customer's specification first.
Lock-in if you build your process around one customer's portal.
Whatever format you use, the invoice still needs all the required invoice elements.
Wondering where US invoicing is heading? Read what US small businesses should know about the future of invoicing.
FAQ:
Is e-invoicing mandatory in the US?
No federal or state law requires B2B e-invoicing. The exception is federal procurement, where agencies have used electronic invoicing since the 2015 OMB memorandum.
Is a PDF invoice an e-invoice?
No. A PDF is readable by people, not automatically by software. It is legally valid, just not automated.
Which format should I use?
Whatever your customer can process. Large customers usually specify X12 EDI or a portal; the DBNAlliance network uses UBL; for everyone else a PDF is fine.
How long do I have to keep electronic invoices?
Generally 3 years after filing the related tax return, longer in specific cases (6 or 7 years) and 4 years for employment tax records.
Do I have to send my invoices to the IRS?
No. The US has no real-time invoice reporting. You only need to produce the records if the IRS asks for them.
