About Us

In 2004, Derek Patterson founded Barnhill Bookkeeping Ltd, offering outsource and onsite bookkeeping services to a varied client base.

Barnhill pride themselves in giving customers a personal service where we will call to their businesses to give advice when required and carry out tasks from basic bookkeeping to full management and financial accounts. When space is at a premium, we can also work off-site and can use remote access if required to gain access to computer records in the clients premises.

We are different from smaller bookkeepers as we do not just provide date-entry services but use the information given to us to help reduce processes, costs and increase efficiencies and productivity.

We are different from Accountants in that we can provide full financial statements but also with a personal service where we are available to explain anything to our clients about their financial requirements.

We also specialise in helping New Startups by giving them advice on all financial aspects of business.

Clients include: Hardware Shops, Pubs, Funeral Directors, sole traders, self-employed, TV Production Companies, Magazine Publishers and International Civil Engineering Companies.

Derek is also credited as Production Accountant on a number of Mint Productions such as “Who do you think you are”, “Haughey” and “Bertie”, which were shown on RTE Television and later released on DVD.

Specialties: Payroll, Bookkeeping, Management Accounts, Tax

We Are Barnhill

Derek Patterson


Derek Patterson was born in Dublin Ireland where he later began his accountancy studies in Plunkett College, Whitehall. In 1988 Derek joined the team at Grant Thornton Chartered Accountants…

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Maria Patterson


Maria Patterson is originally from Dublin and has been a member of the Barnhill Bookkeeping team since its inception. She began her career in Insurance with J. C. Collins & Co Ltd…

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What our clients say about us

  • After upgrading to Quickbooks I was feeling overwhelmed by all of the new features. Derek came to the office to train me and was so helpful. No question was too small as he took me through it step by step and simplified the process” Marese Lynam – Lynam Engineering Ltd
    Marese LynamLynam Engineering Ltd
  • The service that Barnhill provide is ideal for a small-medium sized business such as ours. They are very efficient and professional, yet flexible enough to have adapted their service to suit our changing needs over the last 3 years. We know that thanks to Barnhill, our accounts are in order, our returns up to date and our management accounts accurate, which is very reassuring as a business owner.We would highly recommend them as they were once recommended to us.
    Gayle FouldsProntaprint
  • Having recently started using Quickbooks after using other packages for years I can safely say I am a convert! The training was professional and the trainer extremely knowledgeable on both the package but also accounting and everything was explained in a down to earth & easy to understand manner.
    Sandra Harvey Temple Bar Company
  • I would recommend Derek and Ash / Accountancy Software.ie to anyone considering upgrading or changing their accounts software/package. I couldn’t recommend them enough. Our experience has been a very smooth and rewarding process. I anticipate that we will continue to go to Quickbooks/Accountancy Software.ie in the future. We are delighted to send our business their way!  In my experience you cannot buy this kind of service.
    Lisa NeedhamCorporate Audio Visual Services
  • Barnhill have taken the hassle out of filing my Income Tax for the last couple of years. I give them all the information and they file the return on time and let me know my liability. They are also on hand during the year for advice and answering questions, and no question is too small! I have no problem in recommending their services.
    Eimear HealyFreelance Television Researcher
  • As a newcomer to QuickBooks I called on Derek Patterson to give me some invaluable one to one training. QuickBooks is very user friendly and everything was explained to me in a language which I could understand, which made the learning all the more quicker and far more easier. I wouldn’t hesitate to recommend Derek whenever a bit of training is called for, no question or problem is ever too small and Derek is only a phone call or email away if ever a problem arises.
    MichelleHoward Building Contractors Ltd