Companies with a significant volume of credit/debit card payments rely heavily on payment processors to keep them afloat. Downtime equals lost revenue, so it's not a function easily entrusted to a startup. That's why there are fewer players in this category, and the three established ones (Adyen, Square, Stripe) continue to dominate the U.S. SMB market for third-party solutions. And notably, 2 of the 3 (Adyen, Square) have gone public, further improving trust (Note: we are not including the payment arms Amazon or Shopify here since they primarily serve their own marketplaces).

Interestingly, 4 of the 7 largest players were launched in the past 5 years. But those 4 are much smaller with combined website traffic of under 1M per month. In comparison, the big 3 have 33M to 45M visits per month EACH! And are all 10 to 15 years old.

Years since founding:
10 to 15 years >>> 3 startups
5 to 9 years >>> 2 startups
1 to 4 years >>> 2 startups


Note: We divided the payment providers into four categories:

  1. Charge card and expense management (see list here)
  2. Bill payments and/or invoicing specialists (list here)
  3. Payment processors (below)
  4. Subscription management platforms (coming soon)

NEW: Looking for digital banks, lenders, payment providers, insurance or digital accounting for small businesses? Check out our latest lists: SMB online lenders (33) | SMB challenger banks (12) | SMB insurers (15) | SMB charge cards/expense management (16) | Billpay & invoicing (16)| Payment processors (7) | Subscription processors (7) | SMB digital accounting/bookkeeping (21)

The FAB Score Ranking (Fintech Attention Barometer) is a proxy for the size of a private fintech company.


Table: Top U.S. Payment Processing Challengers* (ranked by FAB score**)

Rank Company FAB Score Review Founded HQ Total Funding Visits (Nov 21)
1 Adyen 5,780 7 Dec '21 2006 Amsterdam 1366 45,100,000
2 Stripe 4,620 7 Dec '21 2010 SF 2200 33,200,000
3 Square 4,500 7 Dec '21 2009 SF 866 35,200,000
4 Fast 157 7 Dec '21 2019 SF 125 790,000
5 Nium 128 7 Dec '21 2015 Singapore 280 80,000
6 Balance 26 7 Dec '21 2020 Tel Aviv 31 35,000
7 PaymentCloud 18 7 Dec '21 2016 LA 10 90,000

Source: FintechLabs, 15 Dec 2021 using data from Crunchbase, SimilarWeb, SEMrush

* We have excluded PayPal from this list because they are more of an enterprise solution, and less importantly were founded in 1998, so a little old/established for a “challenger” list.
**As nerds do, we are developing a proprietary score measuring the adoption of digital financial services at private companies that do not release traditional metrics (# customers, deposits, AUM, etc). We call it the FAB score, standing for Fintech Attention Barometer. The score uses money raised, valuation and website traffic as a proxy for company size and velocity of growth. It’s a work in progress, so expect changes down the road.
**Funding is the amount invested into the company as either equity or debt.

Challenger Payment Providers in the United States


1. Adyen
FAB Score = 5,780
– HQ: Amsterdam
– Founded: 2006
– Went public June 2018
– Raised $1.4B all prior to 2021 (Crunchbase)
– Market cap: $82B (15 Dec 2021)
– Website visits: 45.1M (Nov 2021; SimilarWeb)
– Employees: 2,260 (Pitchbook)
– Articles: 711 (Crunchbase)
– Linkedin: 131k followers (2,480 employees)
– Twitter: 17.6k followers
– Rating: 4.7 (1,890 reviews per FeaturedCustomers)

2. Stripe
FAB Score = 4,620
– HQ: San Francisco
– Founded: 2010
– Raised $2.2B including $600M in 2021 (Crunchbase)
– Website visits: 33.2M (Nov 2021; SimilarWeb)
– Employees: 5,000 (Pitchbook)
– Articles: 3,134 (Crunchbase)
– Linkedin: 383,000 followers (5,910 employees)
– Twitter:  191,000 followers
– Rating: 3.3 (6,810 reviews per TrustPilot)

3. Square
FAB Score = 4,500
– HQ: San Francisco
– Founded: 2009
– Went public Nov 2015 (NYSE:SQ) at $2.9B valuation
– Raised $870M including $11M in 2021 (Crunchbase)
– Market cap: $80.2B (15 Dec 2021)
– Website visits: 35.2M (Nov 2021; SimilarWeb)
– Employees: 5,870 (Pitchbook)
– Articles: 8,245 (Crunchbase)
– Linkedin:  363,000 followers (6,800 employees)
– Twitter: 310,000 followers
– Rating: 4.6  (3,430 reviews per TrustPilot)

4. Fast
FAB Score = 157
– HQ: San Francisco
– Founded: 2019
– Raised $125M including $102M in 2021 (Crunchbase)
– Website visits: M (Nov 2021; SimilarWeb)
– Employees: 300 (Pitchbook)
– Articles: 46 (Crunchbase)
– Linkedin: 15,800 followers (506 employees)
– Twitter:  31,000 followers
– Rating: 4.5 (2,620 reviews per TrustPilot)

5. Nium
FAB Score = 128
– HQ: Singapore
– Founded: 2015
– Raised $221M including $59M in 2021 (Crunchbase)
– Website visits: 80,000 (Nov 2021; SimilarWeb)
– Employees: 600 (Pitchbook)
– Articles:  124 (Crunchbase)
– Linkedin: 53,400 followers (641 employees)
– Twitter:  4,700 followers
– Rating: INA

6. Balance
FAB Score = 26
– HQ: Tel Aviv
– Founded: 2020
– Raised $31M all in 2021 (Crunchbase)
– Website visits: 35,000 (Nov 2021; SimilarWeb)
– Employees: 30 (Pitchbook)
– Articles: 2 (Crunchbase)
– Linkedin:  2,180 followers (40 employees)
– Twitter:  334 followers
– Rating: 5.0 (5 reviews per Capterra)

7. PaymentCloud
FAB Score = 18
– HQ: LA (Sherman Oaks)
– Founded: 2016
– Raised $10M prior to 2021 (Crunchbase)
– Website visits: 90,000 (Nov 2021; SimilarWeb)
– Employees: 75 (Linkedin)
– Articles: 8 (Crunchbase)
– Linkedin:  880 followers (75 employees)
– Twitter: 130 followers
– Rating:  4.6 (16 reviews per Capterra)