Add details on how the grant billing process works

grants/faq.md

@@ -102,3 +102,46 @@ At the end of the review process, one of three outcomes is likely:
 
 Note: Timelines are best-effort and may shift due to holidays, travel, or other
 factors.
+
+## How does the billing process work?
+
+After a grantee is approved:
+
+1. The Linux Foundation Project Manager for GraphQL (PM) will send the grantee
+   the link to US tax forms and wire transfer form (if applicable). The grantee
+   must fill out and return the form to the PM. The completed form must include,
+   at minimum, the legal name, mailing address, tax classification, and tax
+   identification number of the grantee, and be filled out legibly and signed
+   and dated by the grantee.
+   - [W-9 - for US nationals](https://www.irs.gov/pub/irs-pdf/fw9.pdf)
+     (individuals only)
+   - [W-8BEN - for non-US nationals](https://www.irs.gov/pub/irs-pdf/fw8ben.pdf)
+     (individuals only)
+2. If the grantee is not a resident of the US, the grantee completes a wire
+   transfer form and must:
+   - advise which currency to use for payment (USD or local currency) and
+   - confirm that the bank account can receive payment in selected currency.
+   - NOTE: GraphQL Foundation approves, manages and budgets expenses in USD.
+     Payments from GraphQL Foundation **will NOT compensate for currency
+     fluctuations** even if there is a long delay between the date the expense
+     is filed and the date it is paid.
+3. Upon receipt of the completed documents, the PM submits a Purchase Order (PO)
+   request to LF Finance, including the completed W-9/W-8, wire transfer
+   information (if applicable), and supporting documentation for the scope of
+   work and grant amount.
+4. LF Finance processes the contract and PO request. Once approved, LF Accounts
+   Payable issues the contract to the grantee for execution via DocuSign.
+5. The contract is executed when both parties (grantee and LF) have signed. Upon
+   execution, Accounts Payable will issue a **PO number** and the grantee can
+   begin work.
+
+Payment steps:
+
+1. Upon completion of the work, and/or in accordance with grant payment terms,
+   the **grantee submits an invoice** to LF Accounts Payable
+   <ap@linuxfoundation.org>, with copy to the PM.
+   - The invoice must include the information on the linked template:
+     [https://docs.google.com/document/d/1y7vjQA0YZIciabOlgT30I1J5QukprBJVzuaP1P_jHdY/edit?tab=t.0](https://docs.google.com/document/d/1y7vjQA0YZIciabOlgT30I1J5QukprBJVzuaP1P_jHdY/edit).
+   - Information should match what's in the contract/PO.
+2. LF Accounts Payable processes the invoice. Upon approval, LF Accounts Payable
+   issues payment to the grantee.