How do you change Shopify invoice numbers to a sequential series?

Why isn't the Shopify order number a safe invoice number?

Your orders start at #1001, and each new order adds 1. But Shopify's developer documentation says the number “isn't guaranteed to follow a consecutive integer sequence”, or to be unique even within one store. You can't change where the count starts, only add or edit a prefix or suffix.

Shopify Order Printer prints invoices, and its default Invoice template fills the number line with Order {{ order.order_name }}, the order's name. The Order Printer Help pages we read on October 19, 2026 describe no separate invoice counter.

How do you get a separate invoice series?

Use an invoice app that keeps its own counter. Sufio is one example; keep these points in mind:

• The mode: pick Sequential invoice numbers, not Same as order numbers, which reuses each order's number.
• Manual invoices: create them in the same app, so they share that sequence.
• Gaps: Sufio's numbering guide notes that gaps can occur if an invoice is deleted or if the numbering sequence is changed.
• The plan: Sufio's listing places Custom Document Numbering in its Professional plan.

Four other apps (Invoice Falcon, Order Printer Pro, F: PDF Invoice Generator and Vify Order Printer) list “Sequential numbering” as of October 19, 2026; none of their listing texts we read that day says the sequence runs without gaps. Check the numbering settings before your first invoice.

What do EU and UK VAT rules ask for?

EU VAT law requires this detail for VAT purposes on invoices issued under Articles 220 and 221 of the VAT Directive:

HMRC's VAT Notice 700/21 asks full and modified UK VAT invoices for the same thing: “a sequential number based on one or more series”. So a separate series for your Shopify sales is allowed. HMRC's list of details for the shorter invoice it allows for £250 or less (including VAT) doesn't include a number. Whether your tax office also expects no gaps is a question for your accountant.

India's GST Rule 46 also allows “one or multiple series”; GST invoice apps are a separate question.