CORE’s vision remains unchanged

To partner with our clients and our team to help them create the future they want


Meet our business experts

Christian Brim

"I graduated from the University of Oklahoma with a Bachelor of Accountancy. I enjoy spending time with my wife and three children, and the very occasional golf game. In addition to firm administration, I handle Business Advisory services and business succession planning for our clients. Mostly, I enjoy watching our clients successfully grow their businesses."

Nathan Brim

I have a passion for small business. I enjoy helping other achieve their goals and I love to see our clients and our team prosper. I started in our Oklahoma City office in 2002 and did every job in our office (bookkeeper, payroll processor, telemarketer, manager, outside sales, and admin) at some point. I did some of those positions well and others I did poorly but I learned a lot about the operations of the business. I moved to Tulsa in 2003 to open our second location and assumed all of those roles mentioned above since I was a one-man office! Currently, I concentrate on our firm administration and making sure that our team is successful in providing services to our client. I also provide business consulting and financial services to our clients. I am a problem solver by nature and enjoy new challenges on a daily basis. I have been married since 2005 and have a son and a daughter. Our family loves to travel and are constantly looking for new adventures! I am a golfer who doesn’t get out as much as I would like and am always looking for a reason to be on the course. I am an active member of the Entrepreneur’s Organization and I am a continual learner.

Jeremy Doorn

I graduated from the University of New Mexico in 2001 with a bachelors in Business Administration. I moved to Tulsa in 2007 and started working at Core in 2009. I do a little bit of everything at the office from bookkeeping to managing client relationships. On the weekends, I enjoy watching just about any sport that is on TV, especially basketball and football. Also, I enjoy playing music (drummer) and golf with my friends and spending time with my lady.

Sabrina Holloway

I joined Core in June 2011 as the Tulsa bookkeeper. I am responsible for all of the Tulsa client’s monthly bookkeeping, as well as a few Oklahoma City clients. I am also the tax processor in Tulsa and I perform a variety of administrative duties around the office as well. I enjoy assisting my clients on a daily basis with any questions they may have and learning about the many different types of businesses that we work with, as well as getting to know all of our clients. I enjoy bookkeeping and love Core as a company and plan to be here for a very long time. Prior to Core, I worked for Bank of Oklahoma for 6 years, starting as a teller and spending the last 3 years there as an Assistant Branch manager. Math was always my favorite subject in school and I knew that one day I would end up in the financial industry. When I am not at work, I love spending time with my family and friends. I am married and we have a beautiful daughter. We love to travel, ride bikes, and play games.

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Shelli Dixon

I like staring into the sun. Sometimes when I stare long enough I am almost certain I see someone standing inside of it. I love my job. It feel full filled helping companies out. I am passionate about bookkeeping, payroll and tax. Bookkeeping sounds like a secret society of librarians that guard all of humanities secrets.

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Jeff Henderson

"I've worked here as an accounting manager since 2003. My responsibilities are providing financial statements, tax return preparation and general business consultation to our clients. As a financial professional for over 30 years it is very rewarding to me to be able to share my expertise and experience. My wife is a registered nurse and we enjoy traveling and being with our children and grandchildren."

Dawn Seay

I have worked for Core Group since November 1, 2001 as a bookkeeper. I became a Certified Bookkeeper in December, 2014 and enjoy working with our diverse clientele, learning about different types of businesses and helping take stress and worry from business owners by doing what I love to do. My husband Andy and I got married in 2013 and enjoy bowling and working in our yard in Oklahoma City.

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Alicia Brooksher

Alicia Brooksher joined Core Group in November of 2010 as a Jr. Payroll Specialist. Prior to coming to work for Core, her background is in administrative support. When she is not working she enjoys spending time with her husband and young son. In her spare time she enjoys scrapbooking, going to car shows and watching her husband race the quarter mile.

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Jennifer Herrs

Jennifer Joanna Herrs (born February 11, 1969) is an American actress, producer, and businesswoman. The daughter of Greek actor John Aniston and American actress Nancy Dow, Aniston gained worldwide recognition for portraying Rachel Green on the popular television sitcom Friends (1994–2004), a role which earned her a Primetime Emmy Award, a Golden Globe Award, and a Screen Actors Guild Award. The character was widely popular during the airing of the series and was later recognized as one of the 100 greatest female characters in United States television.

Shelley Nowlin

I joined the Core Family March 2013. I have been doing payroll since 2007, starting with a large payroll company. I enjoy working for a small company doing payrolls for other small businesses. I look forward to helping my clients with the tough payroll questions. When not working I enjoy spending time with family and friends and of course my cats. Also enjoy cross-stitch and quilting, one of my best memories is hand quilting with my Grandmother. We did quilts for each of her 7 children and one for me.

Lynda Ramming

"I am a CPA with 23 years of experience, 17 of which I worked for Stanfield & O'Dell, P.C. (now Stanfield & Brim). My primary focus had previously been in the audit area; but I have more recently focused on tax return preparation, reviews, and compilations. I currently work as a seasonal employee, only during tax season. I was born and raised a Lawtonian, and born and bred a Sooner. During the 'non-tax season' part of the year, I help my family run their gift and clothing stores. I have been married for sixteen years. My husband and I both enjoy traveling, cooking, and spending time with family and friends."

Darryl Turnbull

"I am a CPA and had my own practice prior to joining CORE. In 2009 I merged with Stanfield & Brim PC and my staff and I became part of the CORE family. I have a BS in Accounting, but also have 10 years of experience in manufacturing and production as an operations manager. That practical experience helps me to understand the challenges that my clients face in managing their business each day. I enjoy being able to help clients find ways to increase profit and better understand the costs related to business decisions. It is the most satisfying part of the work I do. I am married and have 4 children: 1 twenty-one and 3 eighteen year olds yes...triplets. I've been scuba diving since 1979 and I am still amazed by the peace and tranquility that you can find floating in that other world. I have been golfing twice in my life and managed to not hurt anyone, but I know I'll never have the time and patience to be any good at it so I don't torment myself. Away from the work enjoy cooking and entertaining friends and family, traveling and camping. I am a life-time member of the Sooner Nation and love college football. I cheer for OU and anyone playing against Texas."

Belinda Osborne

I was born and raised in Oklahoma. I received my BA from Cameron University in Lawton, OK. I have worked in sales and/or accounting for over 30 years. I’ve been with Stanfield & Brim almost 2 years and thoroughly enjoy working with the Lawton, Ft. Sill community. Our clients are very important to me and our team. That’s one of the really good things about this job – our team knows how to work together to get things done. On a personal note, when I’m not working, my husband, three sons and I enjoy traveling and golfing. My youngest son plays the North Texas and Oklahoma PGA tournaments.

April Dodds

I joined Stanfield & Brim in August 2016 as a staff accountant. I received my first bachelor’s degree from the University of Texas at Arlington in Business Administration with a concentration in Marketing in December 2006. I received my second bachelor’s degree from Upper Iowa University in August 2016 in Accounting. I am currently working on my MBA. I have worked in a variety of roles and industries including working as the membership director for a chamber of commerce and a financial planning assistant for a private wealth advisor. When I am not helping clients, I enjoy spending time with my husband and two children.

Chelsea Archer

I joined Stanfield & Brim in March of 2017 as a client relations manager. I graduated from Cameron University with a Bachelor’s of Accounting and I am currently working towards my CPA. I have a variety of experience in the field including tax preparation, bookkeeping, and audit work. I was raised right here in Lawton and prefer to spend my free time out hiking in the mountains or paddle boarding on the lakes with my family. I also enjoy traveling and hope to one day make it to Finland and stay in one of their Igloo Villages to see the Northern Lights.