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Invoices and payer instructions

How RailFi invoice IDs, signed payment links and the confirm-twice review help your payer send to the right place.

On this page

In the free beta today, RailFi gives you a USDC invoice template and payer instructions, prepared by a person on the RailFi team. This page explains how RailFi invoices and payment links work.

In beta

Invoice IDs, signed payment links, the payer review page and the test send are in beta for invited contractors.

Invoice IDs

  • Every invoice gets an ID that starts with RAIL-, derived from its details.
  • The same details always give the same ID. A double-click or a retry never creates a second invoice or sends a second email.
  • Reusing an invoice number with different details is blocked with an invoice conflict error.
  • Invoices can't be edited in place. To change one, void it and create a new one, which gets a new ID.

Your payer gets a link like /pay/RAIL-…?t=…. The t part is a signature over the invoice ID, amount, network and address. RailFi checks it every time the page opens, and screens the address against the sanctions list again.

Your payer can also check an invoice ID and address against RailFi's record on the verify page. It answers "Matches RailFi's record" or "Does NOT match. Do not pay."

Link-tampering warning

If the link has been changed, don't pay

If anything in the link has been changed, the page shows only: "This payment link has been changed or is invalid. Do not pay. Ask the contractor to resend it from RailFi." No address is shown.

Scammers edit invoices, PDFs and messages in transit. Never pay an address that appears only in an email, PDF or chat message. RailFi never changes payment details by email.

What your payer sees

Before any sending instructions, the payment page shows who is being paid. Example only:

Payee
A. Contractor
Email
Email verified by RailFi on 30 Sep 2026
Invoice
INV-0042 · RAIL-7Q2M4K9XWD
Amount
1,000.00 USDC
Network
USDC on Base
Address

The page also shows when the address was first used with RailFi. If it differs from the contractor's previous invoice, an amber banner appears: "This payee's address changed on {date}. Confirm with them by phone or video before paying."

RailFi checks format, network and sanctions lists. RailFi does not verify the bank or provider account holder's name; your payee's provider does.

Confirm twice

Your payer confirms the details twice before the sending instructions appear:

  1. Re-select the network from a list, with no default.
  2. Type the last 6 characters of the address, read from their own wallet's confirm screen.
  3. Tick "I will send USDC on {network} only, to this address only."

If the network or the characters don't match, the instructions stay hidden.

Test send

The first send is a small test of 1–5 USDC (the contractor chooses; the default is 1). The contractor confirms in RailFi whether it arrived. The full amount unlocks only after they say yes. If they say no, the page tells the payer to stop. A payer can skip the test only by ticking "I accept the risk of skipping the test", and that choice is recorded. Only the contractor confirms that money arrived; RailFi never sets that on its own. See Invoice statuses.

RailFi emails

  • Every RailFi email to you starts with your 3-word anti-phishing code. If it's missing or wrong, the email isn't from RailFi.
  • Payer instruction emails repeat the invoice ID, amount, network and full address in 4-character chunks.
  • Every email ends: "RailFi never asks for keys, seed phrases or passwords, and never changes payment details by email."

Last updated 30 September 2026. Something unclear or wrong? Tell us.