501(c)(3): the section of U.S. tax code that defines tax-exempt charitable nonprofits. Donations to a 501(c)(3) are tax-deductible for the donor.

ACH: an automated bank-to-bank transfer between U.S. accounts. Free on HCB and usually arrives within a couple of business days.

Account and routing number: your organization's deposit-only bank numbers, used to receive funds from platforms like GoFundMe or Shopify.

API: Application Programming Interface, a way for software to read data from HCB directly instead of clicking through the dashboard. The HCB API is read-only and public.

Card grant: a prepaid spending allowance issued to someone (often by a Hack Club program) that works only at approved merchants.

Determination Letter: the IRS letter confirming an organization's own 501(c)(3) status.

EIN: Employer Identification Number, the IRS tax ID for an organization. HCB organizations share The Hack Foundation's EIN, 81-2908499.

FDIC: the U.S. agency that insures bank deposits. HCB's partner banks are FDIC insured.

Fiscal sponsorship: operating as a project under an existing nonprofit's 501(c)(3) status instead of starting your own.

The Hack Foundation: Hack Club's legal name, and the 501(c)(3) that fiscally sponsors HCB organizations.

HCB transfer: a fast, free transfer of funds between two HCB organizations.

Invoice: a payment request you send to a sponsor or customer to collect money.

Receipt: an itemized proof of purchase showing the merchant, date, items, total, and proof of payment. HCB requires a valid receipt for every transaction.

Reimbursement: paying someone back with HCB funds for something they bought for the organization with their own money.

Transparency mode: an optional setting that makes your organization's transactions publicly viewable.

URL slug: your organization's short identifier in HCB web addresses, the part after hcb.hackclub.com/ (for example, hcb.hackclub.com/yourslug). It also forms your donation page link.

W-9: a U.S. tax form that provides an organization's tax information to whoever is paying it. Hack Club has a prefilled one you can share.

W-8 BEN: the tax form used by a non-U.S. individual or entity being paid by a U.S. organization.

Wire: a bank-to-bank transfer, including international ones. HCB's partner bank charges $25 per wire.

Wise: a service HCB supports for lower-cost international transfers to selected countries.