Overview
You can add custom query parameters to your payment page link so certain fields are already filled in when your payer arrives — no extra typing required on their end. This works on general payment page links, Connect links, and item-based payment links. To get started, follow the steps below:
Turning on URL pre-fill
Log in to LawPay (or ClientPay).
Go to Payment Pages.
Click Edit on an existing page, or create a new one.
Scroll to the URL Settings section.
Check Enable pre-fill from URL parameters to turn the feature on.
Decide whether payers can change a pre-filled value once it's on the page:
Leave Allow payers to edit pre-filled fields checked if you want payers to be able to update a value you've pre-filled.
Uncheck it if you want pre-filled fields to be locked. Any field that isn't pre-filled will still be editable either way.
Click Save.
Choosing which fields can be pre-filled
Under Default Fields or Custom Fields, you'll see the fields available for your payment page. For each one, set a status of Off, Optional, or Required to control whether it appears on the page at all.
Once a field is set to Optional or Required, a text box appears underneath it showing the query parameter name mapped to that field — for example, order_number for Order Number. You can leave the default name as-is or rename it to something shorter or easier to remember. Renaming it doesn't break the connection to that field, and it won't change the field's label on the payer-facing page — it only changes what you type in the URL.
Note: A field set to Off won't appear on the payment page, so it can't be pre-filled or edited.
Building your pre-filled link
Once your fields and parameter names are set, add them to the end of your payment page URL using a ? before the first parameter and an & between each additional one.
Example: To send a payer a link with the Order Number and City & State already filled in:
When the payer opens this link, they'll see Order Number and Amount already populated — and, depending on your Allow payers to edit pre-filled fields settings, either able or unable to change them.
Frequently Asked Questions
Does this change what my payer sees on the page? No. Pre-filling only supplies a value for a field that already exists on your payment page — it doesn't add, remove, or relabel fields.
Can I use different parameter names for different payment pages? Yes. Query parameter names are set per payment page, so you can customize them independently for each one.
What happens if I leave "Allow payers to edit pre-filled fields" unchecked? Pre-filled fields become read-only for the payer. Any field on the page that wasn't pre-filled through the URL stays editable as normal.
How are amounts formatted? Amounts are formatted as “cents” (without decimals). So if you want to pre-fill the amount $100.00, in the URL you would use ?amount=10000