TL;DR
For nonprofits accepting under $50K in monthly donations, PayPal's confirmed charity rate and Stripe's nonprofit program lead on published pricing. Above that volume, Helcim's interchange-plus structure usually beats both on effective rate. Square wins for in-person fundraisers and church collections where hardware needs to ship the same week. Stax becomes competitive above roughly $100K monthly when the $99 subscription is dwarfed by the percentage markup it replaces. The right pick depends on average gift size, recurring versus one-time mix, and whether the team has a developer.
How we ranked
We compared each processor on six criteria that matter to nonprofits, not retailers. First, the published effective rate at three donation volumes: $10K, $50K, and $250K monthly. Second, whether the provider passes interchange through directly (IC-plus) or buries it inside a flat rate, per published Visa interchange schedules and Mastercard interchange tables. Third, recurring donation tooling: subscription billing, donor-managed card update, dunning on declined renewals. Fourth, fee-absorption options that let donors cover the processing cost at checkout. Fifth, contract length, early termination charges, and month-to-month availability. Sixth, dispute and chargeback handling for refund requests on donations.
We did not weight features like loyalty programs, gift cards, or inventory management. Nonprofits rarely use them. We also discounted hardware bundles unless the organization runs in-person events. Rates and terms come from each provider's public pricing page as of May 2026.
At a glance
| Provider | Headline pricing | Contract | Settlement | Best for | Watch out for |
|---|---|---|---|---|---|
| Stripe | 2.9% + $0.30 online, 2.7% + $0.05 in-person | None | 2 business days | Custom donor flows, international currencies | No phone support on free plan |
| Square | 2.6% + $0.10 in-person, 2.9% + $0.30 online | None | 1 business day | Galas, auctions, in-person collections | Weak recurring donor tooling |
| Helcim | IC + 0.50% + $0.25 online, IC + 0.40% + $0.08 in-person | None | 2 business days | $25K to $1M monthly, mixed channels | Smaller app marketplace |
| PayPal | 1.99% + $0.49 confirmed charity rate | None | 1 business day | Donation buttons, donors who recognize the brand | $0.49 fixed fee on small gifts |
| Stax | $99/mo + IC + $0.08 in-person, + $0.18 online | Month-to-month | 2 business days | $100K+ monthly, stable volume | Subscription kills small months |
Stripe
Stripe charges 2.9 percent plus $0.30 per online transaction under standard pricing, per its published rates. Registered 501(c)(3) organizations can apply to Stripe's nonprofit program for a discounted rate on charitable transactions. The discount is not published as a fixed number; eligible nonprofits negotiate based on volume.
Recurring donations run through Stripe Billing, which adds 0.5 percent on subscription invoices unless the organization sticks to the core Payments product and rebills through the API. Stripe Checkout supports donor cover-the-fee logic through a single Boolean parameter on the session object, making fee absorption trivial to implement.
No monthly fee, no contract, no early termination charge. Settlement runs on a two business day rolling basis for new accounts. Stripe fits nonprofits that have a developer on staff or contract. The dashboard is dense, the API is well documented, and the platform handles donations across 135 currencies. Avoid Stripe if the organization needs phone support during a campaign weekend or wants a turnkey donate button without writing code.
Square
Square charges 2.6 percent plus $0.10 per dipped or tapped card, per its pricing page. Keyed transactions, including most online donations not routed through Square Online, run 3.5 percent plus $0.15. Online donations through Square Online or Square Checkout sit at 2.9 percent plus $0.30.
Square does not publish a nonprofit discount. Registered 501(c)(3) organizations pay the same rates as for-profit merchants. Square's strength is the free POS app, the same-day Square reader hardware, and one business day settlement on a Square checking account.
For nonprofits running in-person galas, charity auctions, or church collections, Square is the fastest path to swipe a card without hardware lock-in. The Square Reader runs $49 for chip and tap. No monthly fee on the base plan.
Avoid Square if recurring donations are the core revenue model. Square's subscription billing was built for retail subscriptions and lacks dunning, card-updater support across all networks, and donor-managed billing portals. For one-time event giving, Square is fine. For monthly sustainer programs, look at Stripe or Helcim.
Helcim
Helcim publishes interchange-plus pricing at IC + 0.50 percent + $0.25 online and IC + 0.40 percent + $0.08 in-person. There is no monthly fee, no contract, no early termination clause, and no per-merchant gateway charge.
The published margin auto-tiers down as monthly volume rises. At $25K monthly, the effective online rate sits near 2.7 to 2.9 percent depending on card mix. At $250K, the same card mix prices closer to 2.3 to 2.5 percent, consistent with average interchange ranges reported in Federal Reserve payments studies.
Helcim's recurring billing supports donor-managed payment updates, dunning on declined cards, and webhook events for accounting integration. The platform passes Level 2 data on commercial cards automatically, which lowers interchange on corporate donor cards by 0.10 to 0.50 percent depending on Visa and Mastercard category.
Helcim fits nonprofits processing $25K to $1M monthly that want a published rate card and no sales-rep haggling. The platform does not offer a fixed nonprofit discount because the IC-plus structure already strips out the markup that other processors use to fund discount programs. Avoid Helcim if the team needs an extensive third-party app marketplace.
PayPal
PayPal publishes a confirmed charity rate of 1.99 percent plus $0.49 per donation for registered 501(c)(3) organizations, per its business fees page. Standard PayPal Checkout for non-charity accounts sits at 3.49 percent plus $0.49.
The confirmed charity rate applies only to donations processed through PayPal's charity-specific products: PayPal Giving Fund and the PayPal Donate button. Sales of merchandise, event tickets sold to non-members, and sponsorship payments fall back to standard commercial rates.
Settlement is one business day to a PayPal balance, then one to three business days to a linked bank account. No monthly fee on standard PayPal Business. PayPal fits nonprofits whose donors expect a familiar PayPal or Venmo button at checkout. Donor recognition of the brand can lift conversion on the donate page. Avoid PayPal as the sole processor if the organization runs an online store, sells event tickets at scale, or accepts B2B donor payments above $5K per transaction.
Stax
Stax charges a flat $99 monthly subscription plus interchange plus $0.08 per in-person transaction or $0.18 per online transaction. No percentage markup above interchange.
For nonprofits processing under $20K monthly, the subscription rarely pays back. At $50K monthly, the subscription begins to cover itself against the percentage markup that a flat-rate processor like Stripe or Square would charge. At $250K monthly, the savings versus Stripe standard pricing typically clear $9,000 to $14,000 per year, before any negotiated nonprofit discount.
Stax does not publish a separate nonprofit rate. The model relies on the subscription replacing the percentage markup entirely, which is structurally similar to a wholesale processor.
Recurring billing runs through the Stax platform with donor-managed payment update via a customer portal. Phone support is 24/7. Stax fits nonprofits processing $50K or more monthly that have stable, predictable donor volume. Avoid Stax if monthly donations swing widely month to month: the $99 fee is fixed regardless of volume, so a slow quarter at $5K monthly inflates the effective rate. Also avoid Stax for organizations that want a no-contract, no-monthly-fee structure for cash flow simplicity.
Verdict
For nonprofits under $50K monthly donation volume, PayPal's confirmed charity rate at 1.99 percent plus $0.49 is the cheapest published option, provided most gifts are $50 or larger. Below $50 per gift, the fixed $0.49 component pushes the effective rate above 3 percent, and Helcim's interchange-plus structure usually wins.
For nonprofits above $50K monthly, Helcim leads on effective rate without a contract. Stax becomes competitive above $100K monthly when the $99 subscription is dwarfed by the percentage markup it replaces. Stripe wins where developer integration matters: custom donor flows, international currencies, cover-the-fee checkout logic. Square wins for in-person fundraisers and church collections where hardware needs to ship same week.
The mistake to avoid: signing a multi-year contract for nonprofit processing. Every provider in this comparison offers a no-contract option. There is no operational reason to lock in for 36 months.