> ## Documentation Index > Fetch the complete documentation index at: https://docs.boomfi.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Paylink Features > Prefill, customer_ident, redirects, variants, and managing payment links. Payment links support query parameters and variant URLs so you can tailor checkout without creating a new link for every customer. Topics: * [Prefill customer data](#prefill-customer-data) * [Customer fields a merchant can collect](#customer-fields-a-merchant-can-collect) * [Connect a customer (`customer_ident`)](#connect-a-customer) * [Redirect after payment](#redirect-after-a-successful-payment) * [Change amount and currency (variants)](#change-amount-and-currency) * [Manage pay links in the dashboard](#manage-pay-links) Your base pay link URL is returned when you create a pay link (hosted checkout host + link id). Hosted checkout for this environment is rooted at `https://pay.boomfi.xyz`. Below, `` means that full URL (for example `https://pay.boomfi.xyz/`). ## Prefill customer data Append identity query parameters so the customer does not re-type data you already hold. Checkout always collects name and email. The other parameters apply only when that field is enabled on the paylink (see [Customer fields a merchant can collect](#customer-fields-a-merchant-can-collect)). ```text theme={null} ?name=Tamara&email=tamara@example.com&nationality=GB ``` | Field | Description | Required | | - | - | - | | `name` | Full name | Yes when prefilling | | `email` | Email address | Yes when prefilling | | `dateOfBirth` | Date of birth, ISO 8601 `YYYY-MM-DD` | Conditional\* | | `nationality` | Nationality as ISO 3166-1 alpha-2 (`GB`, not `GBR` or a country name) | Conditional\* | | `placeOfBirth` | Place of birth, free text | Conditional\* | | `address1` | Address line 1 | Conditional\* | | `address2` | Address line 2 | Conditional\* | | `city` | City | Conditional\* | | `state` | State / province | Conditional\* | | `postalCode` | Postal / ZIP code | Conditional\* | | `country` | Country of the address, free text | Conditional\* | | `phoneNumber` | Phone in international format | Conditional\* | \*Required only when the paylink collects that field. Name and email are always collected. An unknown `nationality` value, including an alpha-3 code or a country name, is ignored and the customer chooses a country from the list. `nationality` is separate from `country`. `country` is the address country. `nationality` is the payer's nationality, chosen from a country list at checkout. Prefill only accepts alpha-2. On the payment, `customer.nationality` may be alpha-2 or alpha-3, and the customer record stores alpha-3 (`GB` is stored as `GBR`). ## Customer fields a merchant can collect Turn extra fields on in the dashboard under **Collect customer information**, or set `metadata.customer_fields` when you create or update the paylink. Checkout always asks for name and email, whether or not they are in the list. Allowed values: | `customer_fields` | Checkout collects | Prefill parameters | | - | - | - | | `address` | Address line 1, city, postal code, and country. Line 2 and state are optional | `address1`, `address2`, `city`, `state`, `postalCode`, `country` | | `date_of_birth` | Date of birth | `dateOfBirth` | | `nationality` | Nationality | `nationality` | | `phone` | Phone number | `phoneNumber` | | `place_of_birth` | Place of birth | `placeOfBirth` | | `name` | Full name (always shown) | `name` | | `email` | Email address (always shown) | `email` | `address` is one value. It turns on the whole address block, not a single line. An unknown value is rejected when you save the paylink. ## Connect a customer Bind the session to a customer id you already store with `customer_ident`: ```text theme={null} ?customer_ident= ``` Webhook and dashboard activity can then use this identifier consistently. ## Redirect after a successful payment Configure redirects on the paylink with first-class `after_completion` when you create or update it (`type: redirect`, `redirect_url` for success, optional `failure_redirect_url` for expiry or Failed). Get and list paylink responses return the same object. You can also pass `redirect_to` with a URL-encoded destination. If the pay link itself has no redirect configured, the query value is used. ```text theme={null} ?redirect_to= ``` ### Skip redirect delay By default a short countdown (about 10 seconds) runs before redirect. Skip it with: ```text theme={null} ?redirect_to=&skip_redirect_delay=1 ``` ### Payment id on redirect The redirect destination receives a `pid` query parameter with the payment id so you can fetch payment details from the API: ```text theme={null} https://your.example.com/thanks?pid= ``` Use the payment-by-id endpoint on `https://mapi.boomfi.xyz/v1` with your API credentials. See the Payments operations in the API reference. ## Change amount and currency Generate a **variant** URL when the quoted amount or currency must change at send time (top-ups, tips in addition to a base amount, alternate quote currency): * Call the **Generate variant URL** paylink endpoint (see API reference) * Pass `amount` and/or `currency` * Optionally pass `customer_ident` and `redirect_to` ## Manage pay links Open: `https://app.boomfi.xyz/dashboard/pay-links` BoomFi payment link detail From a pay link detail page you can: * Inspect main, link, and checkout settings * Review transactions on that link * Edit most fields via the overflow menu, or deactivate the link You cannot change a one-time link into recurring (or vice versa) after creation: create a new link instead. ## Related * [Payment Links](/payments/paylinks) * [Account-Specific Paylinks](/payments/account-specific-paylinks) * [Checkout](/payments/checkout) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.