Clients are not just
numbers to us

Quote from client: “You’re my people.”

Since our inception we have maintained the highest standards of quality and ethics in all that we do.

The roots of this practice go back to the early 1970s when F. David Bush, CA was in practice just down the street from where the current office is. Many of the clients who were with Dave at that time are still with the current practice.  Some are still in business, and some of the businesses have been passed down to children who have become new clients.

Karen Mercier took over Dave Bush’s practice in September of 2000. Dave was to stay on indefinitely in a part-time capacity but sadly passed away the following year. The practice grew steadily over the next 5 years to the point where Karen could not take on more clients without another professional to help. In 2005, Karen re-connected with Alice Tay, a Certified Management Accountant whom she had worked with at Imperial Oil, and convinced Alice to come on as a partner. They spent a year working together to test the waters and in 2007, the partnership was officially formed. This was a perfect match and now, years later, the partnership is as solid as ever. Karen and Alice agree on pretty much everything, including that it’s perfectly ok for accountants to wear jeans to work whenever they want. Both believe that excellent service includes being available to the clients and having hands-on involvement in the work done.

The Mercier Tay accounting practice provides services to a varied array of corporate clients. Many of these clients provide services to the oil patch including welding, consulting, trucking, safety services, construction and maintenance. The practice also provides services to clients in retail, restaurants, other professional services and general trades, holdings and investments, land development as well as a number of non-profits.

As well, the practice prepares a great number of personal tax returns from the simple (1 slip) to the complex including farms, proprietorships, and rentals.

Bonnyville Alberta accounting services

“We take pride in the long-term relationships we’ve built with our clients.”

Karen Mercier + Alice Tay



  • Karen Mercier, CPA, CGA
    Karen Mercier, CPA, CGA PARTNER

    Karen was born and raised in Bonnyville. After graduating with an Honours diploma in Business Administration from NAIT in 1981, she enrolled in the CGA program and received her designation in 1984. During the 3 years of completing the CGA program, she worked in public practice for Brian Maguire, a Chartered Accountant who practiced in Bonnyville. In 1984, she was offered a job by Imperial Oil Resources (IOR) to work at their Cold Lake Operations site in the accounting department. The next 15 years, during which IOR developed and expanded their Cold Lake facilities, she worked in various positions of increasing responsibility. By 1997, she was a member of the operations management team in the position of Business Services Manager, responsible for all production accounting, local cost accounting and business controls. The next rung on the ladder led to Calgary… which wasn’t in the cards… which led to a call to Dave Bush, who had previously approached Karen about taking over his practice. In September of 2000, ready for a new challenge, Karen took over Dave’s practice.

  • Alice Tay, CPA, CMA
    Alice Tay, CPA, CMA PARTNER

    Alice grew up in an entrepreneurial household which operated multiple small family businesses. At age twelve, she immigrated with her family to Canada where they continued the family tradition of small business ownership. She later took a leave from university studies to start up and operate a manufacturing plant for her family in Nebraska, USA. In 1992, she graduated from the University of Manitoba with an Honours degree in the Bachelor of Commerce program. She was recruited out of university by Imperial Oil, working first in Calgary then transferring to the Cold Lake Operations site where she worked in Karen’s team. In 1996, she received her designation as a Certified Management Accountant.  During the same year, she joined Deloitte and Touche Consulting Group (and later operated an independent consultancy) to provide expertise in the implementation of financial systems and processes, and business intelligence analytics. Throughout this time, she maintained her home base in Bonnyville while working across North America. Weary of the extensive travel and ready for a change, Karen’s timely partnership offer took root and Alice happily made the leap in 2006 to join Karen’s practice.

  • Maureen Lotsberg
    Maureen Lotsberg CPA, CA, CFP

    Maureen grew up in the Glendon area. She graduated from the University of Alberta with a Bachelor of Commerce in 1993. She started work at the office of the Auditor General of Alberta in Edmonton, auditing government departments and institutions. In 1995 she moved to Red Deer and joined the public practice of Ladell Perry which would eventually become Collins Burrow. She worked with clients ranging from small businesses to not-for-profits. Maureen obtained her Chartered Accountant’s designation in 1997 and her Certified Financial Planner designation in 1999. In 2001 Maureen and her husband decided it was time to move closer to family so they packed up and moved to Bonnyville. Maureen started working with a local chartered accounting firm in 2002. She continued there until 2014 when she accepted an opportunity to be the Controller for a local oilfield business. With the downturn in the oilfield industry, she jumped at the opportunity to work with Mercier Tay LLP and joined the firm full time in late 2015. Maureen brings to the firm many years of experience in public practice with a wide variety of clientele.


  • Donna Brosseau
    Donna Brosseau Senior Accounting Technician

    Since 2002

  • Jillian Rusnak
    Jillian Rusnak Senior Accounting Technician

    Since 2011

  • Darlene Rivard
    Darlene Rivard Accounting Technician

    Since 2010

  • Airilea Mackenzie
    Airilea Mackenzie Accounting Technician

    Since 2012

  • Lorraine Ryden
    Lorraine Ryden Accounting Technician

    Since 2012

  • Claudette Popowich
    Claudette Popowich Office Administrator

    Since 2011