- Short answer
- Additional details is the text Shopify shows next to your manual payment method in checkout — before the order, unlike Payment instructions.
- The other field on the form
- Payment instructions is separate: its text shows on the order confirmation page, after the order is placed.
- Three fields or two
- Shopify's custom-method steps name three fields; its suggested-method steps name only two.
- The worked example Shopify gives
- Email money transfers (Canada): the email address plus the secret question and answer, in both boxes.
- Length, HTML, blank field
- No character limit, HTML rule, blank-field behaviour or optional label on the three pages we read.
What the Additional details field is
A manual payment method is arranged outside the checkout, so its setup form is about what the buyer is told, not how money moves. Setting up a custom method names three fields — Custom payment method name, Additional details and Payment instructions — and Additional details is free text you write yourself.
Shopify's steps for a suggested method — one of the ready-made options in the list — name only two of those fields, Additional details and Payment instructions, with no step for entering a name.
Your customer sees it in checkout, before the order
Where and when the text appears is a single sentence on Shopify's manual payments page.
In Additional details, enter any information that you want displayed next to the payment method in your checkout.
Checkout is the only surface that sentence names, and it fixes the moment too — the order has not been placed yet. Payment instructions is the other box: its text lands on the order confirmation page after your customer completes the order.
What to put in it, and what the pages we read leave open
On the pages we read, Shopify gives one worked example of what to put there, and it is for email money transfers, a method it documents for stores in Canada: the email address the customer sends the money to, and the secret question and answer they should use. Shopify asks for the same information in Payment instructions as well, so the example is not a choice between the boxes.
How long the Additional details text may run, whether it accepts HTML, what happens if you leave it blank, and whether the admin marks it optional are not stated on the manual payments page, its email money transfers page or the Payments page we read on August 22, 2026. What Shopify does state is where each box prints, and that is the practical difference — the checkout box is the one a buyer reads while still choosing how to pay, and the confirmation page comes only after the order.
This article was written entirely by AI under human editorial direction. The editor sets the topic and structure, runs multi-stage validation on facts, links, and interactive elements, and verifies the output is useful from a business perspective. All claims are checked against official Shopify sources. Details may change — always confirm critical data at shopify.com.
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