Matt Parson
Analyst · SMBC
Thanks, Dushyant. As a reminder, today's discussion includes non-GAAP financial measures. Please refer to the tables in our press release and supplemental slides for a reconciliation of non-GAAP items to the most directly comparable GAAP financial measure.
In the second quarter, we processed 89.5 million transactions, which is a 39.4% increase over the same period last year. Transaction volume was driven by Biller Direct with tailwinds from IPN, Payveris and B2B transactions. The transaction growth led to a revenue increase of 28.3% in the quarter, which resulted in revenue of a $120 million. Contribution profit was $48.7 million, representing a 30.1% increase over Q2 last year.
Consistent with the last several quarters, contribution profit grew a little faster than revenue, primarily due to an increased mix of transactions without interchange, specifically IPN transactions and B2B transactions. Contribution profit per transaction was $0.54, which was consistent with the past 2 quarters and our expectations. As we said multiple times in the past, fluctuations in areas outside our control like average payments or payment mix can impact contribution profit on a quarter-to-quarter basis.
Historically, we have seen these things even out on a full year basis. However, given the ongoing economic uncertainty, we will continue to monitor these things very closely in the back half of the year. Adjusted gross profit increased $8.6 million or 28.6% in the quarter to $38.7 million. Adjusted EBITDA was $5 million for the second quarter, which represents a 10.3% adjusted EBITDA margin, which was a little softer than we expected primarily due to wage inflation.
Operating expenses rose $13.2 million to $38.1 million for Q2 of 2022 from the same period last year. Overall, the increase in operating expenses from last year was driven by investments in staffing as well as additional operating expenses associated with Payveris and Finovera, the amortization of identified intangible assets from the acquisitions and stock-based compensation.
Specifically R&D expense increased $2.3 million from the second quarter in 2021 to $10.2 million. Sales and marketing increased $8.3 million, driven by the Payveris acquisition, continued expansion of the sales team, adding partnerships to capture our sizable market opportunity and an increase in stock-based compensation.
We experienced an increase in G&A expense of $2.6 million via our acquisition, multifold increases in the cost of corporate insurance and ongoing investment in public company infrastructure. Our GAAP net loss was $2.5 million and EPS for Q2 was negative $0.02. Non-GAAP net loss was $400,000 and non-GAAP EPS was 0 for the quarter.
As of June 30, 2022, we had a $158.3 million of cash and cash equivalents for our balance sheet. Cash decreased primarily due to the timing of certain customer payments as well as increased operating expenses due to the acquisitions. At quarter end, we had approximately 122.6 million shares of common stock outstanding.
Now turning to our 2022 full year outlook. Coming into Q2, we were comfortable with the guidance we gave. As Dushyant mentioned earlier, elongated implementation of onboarding times and this economic environment has created slower-than-expected net revenue recognition for the second half of 2022 of approximately $6 million to $8 million. But this revenue is not lost. It's just shifted into future quarters with the contract terms and TCV remaining the same.
The inflationary environment has also compressed our contribution profit by a couple of million dollars. We were able to recapture some of the inflationary impact with price adjustments, some of which is already in process, but it takes a bit of time to recognize the impact.
Based on these factors, we're changing our 2022 revenue outlook to the range of $485 million to $492 million. We're also changing our contribution profit guidance to be between $200 million and $204 million for the year, which is approximately 26% to 29% growth. We broadened the range due to the economic uncertainty, specifically the uncertain timing on implementation and potential for ongoing inflation.
Just to provide some context on the stretched out implementation, in our Q3 call last year, we told you about a large new client win that would add 400 basis points to our then revenue run rate. It was our expectation that this client would go live in Q3 of this year. However, that client has now rescheduled to go live to 2023. We also have one other large implementation that has done the same. To be clear, we aren't expecting any loss of revenue associated with these clients. It's simply starting later than was originally anticipated, and we expect to start recognizing this revenue in 2023.
We expect these delays to have a bigger impact on Q3, combined with the fact that Q3 is a lower contribution margin quarter seasonally. As a result, we anticipate little to no sequential contribution profit growth over Q2. Our adjusted EBITDA outlook is now in the range of $25 million to $29 million with an adjusted EBITDA margin of 13% to 14%. We are seeing ongoing wage pressure in our current workforce due to the levels of inflation, which is also putting some short-term pressure on our EBITDA margins.
In addition, after seeing the current sales momentum, we expect to make additional investments in our sales and marketing efforts. Our current guidance reflects some assumptions around continued inflation and potential for increasing wage pressure, further expected delays in implementations could also impact our ability to meet our guidance. To be clear about our guidance, we widened our range to provide a better view on the spectrum of scenarios given the increased economic uncertainty. We expect to finish the year in the ranges we've laid out.
Finally, as we said last quarter, we would anticipate our full year effective tax rate to be around 30%. However, due to the amortization of intangibles associated with the acquisition, the closer we are to breakeven on pretax book income, the more variation we could see on our tax rate. In addition, the permanent tax benefit from stock-based compensation continues to impact the rate.
I'll now turn the call back over to Dushyant for some closing comments.