Payveris serves over 265 national institutions.
And what that means to Paymentus is that this allows us to accelerate our IPN strategy for banks by having nearly 300 financial institutions join our network.
In addition to that opportunity, there is another equally exciting opportunity where each of these nearly 300 FIs can be direct billers on our platform, which will add to our existing base of direct billers.
Revenue grew 30% over the same period in 2020 to $93.5 million.
Q2 contribution profit grew 25% to $37.4 million.
Adjusted gross profit in the quarter was $30.1 million, which was a 24% increase over Q2 of last year.
And the transaction processed grew over 39% year over year.
In the second quarter, we also continue to build on our more than 350 integrations divisions by adding new partners, including completing an integration with a leading provider of software to midsized telecommunication companies.
Two examples of expansion are a large utility with over 2 million customers, which added advanced payment methods like PayPal to provide their customers with more choices.
We are also really excited about IPN across -- other IPN partners, and especially, our extended reach to nearly 300 financial institutions with the Payveris transaction.
For example, we would receive a $1.50 for a utility payment of $50 and the same $1.50 for a payment of $275.
We processed $64.2 million transactions, representing a year-over-year increase of approximately 39%.
This transaction growth drove a 30.3% increase in revenue over the same period in 2020, which resulted in revenue of $93.5 million.
Contribution profit for Q2 was $37.4 million, a 24% increase over the same period last year.
Adjusted gross profit for the second quarter was $30.1 million and this was an increase of 24% from Q2 of 2020.
Adjusted EBITDA was $8.3 million, which represents a 22.2% margin on contribution profit.
The 5% decline in adjusted EBITDA from the second quarter of 2020 is due to cost increases related to being a public company, as well as increased investments in R&D and sales and marketing.
Operating expenses rose $7.8 million to $24.8 million for Q2 of 2021.
R&D expense increased $1.9 million or 32.4% as we continue to invest in new features and functions in our payments platform and we build out IP with additional partners.
Over half of the operating expense increase, or $4 million, was in G&A and was driven by public company cost, as well as continuing to build out the public company infrastructure.
Sales and marketing increased $1.9 million or 24.5% as we ramped up selling activity relative to the same time last year in the middle of the COVID uncertainty.
These two one-time tax items totaled approximately $2 million or about $1 million each.
As a result of these two discreet one-time items that hit GAAP tax expense in our Q2, our effective tax rate for the quarter was approximately 86%.
Excluding these two discreet one-time tax items, our net income for the quarter would have been $2.6 million.
As of June 30, 2021, we had $266.4 million of cash and cash equivalent on our balance sheet.
Inclusive of our Payveris and Finovera acquisitions, our revenue outlook for 2021 is in the range of $378 million to $382 million, which represents growth between 25% and 27% year over year.
For contribution profit, our full-year outlook is between $152 million and $154 million, or approximately 26% to 28% growth.
For full-year 2021, we also see adjust EBITDA in the range of $25 million to $28 million, with an adjusted EBITDA margin of 16.5% to 18.5% on contribution profit.
However, as a result of the items mentioned for Q2, we expect that our full-year effective tax rate for 2021 will be approximately 47%.

Summary:
This transaction growth drove a 30.3% increase in revenue over the same period in 2020, which resulted in revenue of $93.5 million.
Inclusive of our Payveris and Finovera acquisitions, our revenue outlook for 2021 is in the range of $378 million to $382 million, which represents growth between 25% and 27% year over year.