For Kate Hillis, the shift from successful design engineer to wet-behind-the-ears patent attorney trainee was humbling. "From having a reasonably high degree of responsibility, I was suddenly not able to even send an e-mail without it being checked by my boss," she says.
The loss of stature wasn't the only disadvantage of the career change. She also suffered an initial drop in income, and she knew that years of arduous study lay ahead. But she saw these obstacles as potential "short-term pain for long-term gain," she says. And if patent law didn't pan out, she figured, she could always return to engineering.
Seven years later, Hillis is a fully fledged patent attorney, leading her own company, Opus Patent Services , at the tender age of 32.
Hillis says she first decided to become an engineer at the age of 12, during a Smallpeice Trust  engineering course where she built bridges with drinking straws and heard a talk by a female engineer that struck a chord. "I went to an all-girls school, which taught sewing rather than woodwork, but this talk showed me that engineering was a realistic career option for me," she says.
Hillis went on to do a 4-year combined bachelor's and master's degree in mechanical engineering at the University of Bristol , which was sponsored by Airbus U.K. , where she worked during summer holidays and a gap year. After graduating in 2001, she continued working for Airbus U.K. in Bristol for 4 years as a design engineer.
Despite her involvement in high-profile projects, such as the design of the wing structure for the world's largest passenger aircraft (the Airbus A380), Hillis grew "disenchanted" with the job, she says. "Much of the interesting technical work was being done abroad, leaving U.K.-based engineers to perform more of a coordinating role," she explains. She missed dealing, literally, with the nuts and bolts.
Hillis began to apply for other engineering jobs, even as she explored alternative careers. She grew increasingly interested in patent law, which would allow her to exercise her technical chops and "to play with words," she says.
She sought a way in but found no university courses in Europe that would take someone through to qualification as a U.K. or European patent attorney. "There are courses that will help you to get part of the way there, but most trainees are sent on these courses once they have a training place with a firm," Hillis explains. In 2004, she joined the patent law firm Mewburn Ellis LLP  and completed a 3-month Certificate in Intellectual Property Law at Queen Mary, University of London , as part of her 5 years of training. She relocated several times during training, as company policy says all trainees must spend time in different offices. "I spent a year in Cambridge, a year in London, and then settled in their Bristol office," Hillis says.
After completing her training and passing the exams set by the Joint Examination Board 
The role of a patent attorney is, broadly, to help clients file patents for technological findings or inventions. "The job is mainly a solo affair and involves careful scrutinizing of documents, such as patent applications for similar technologies, reflective deliberation about how the client's invention is different, and working out how to craft the wording of the patent claim," Hillis says. "You need to have a good writing style, and you also have to deal with clients and inventors, so you need to be good with people."
Once, language skills were essential for a European patent attorney. When she was taking her exams, she had to understand a patent document written in either French or German, the two official languages of European patent law other than English. (She opted for French and passed.) But because this regulation was a barrier for aspiring European patent attorneys from countries that don't have English, French, or German as a national language, this requirement no longer exists. "Language skills are mainly useful for dealing with foreign clients, who may be very pleased to have a patent attorney who can talk to them in their native tongue. From this perspective, some knowledge of Japanese or a Chinese dialect may be particularly useful nowadays," Hillis says.
Hillis grew up in the English countryside, near Winchester, and after several years of urban life she was eager to return to the country. With the vast majority of patent law firms being based in London, Hillis says she had to "think outside of the box." At the end of 2009, she began to consider becoming a sole practitioner.
She spotted what she believed to be a gap in the market: à la carte professional patent advice. Commonly available patent law services, she says, fell into two categories: "patent attorney firms who offer a full service [and] completely manage the patent application from start to finish" and "a number of unqualified individuals describing themselves as patent consultants," Hillis says. "I thought that many smaller businesses and start-up enterprises would value the advice of a qualified patent attorney without committing to the full service."
This, she decided, would be her company's unique selling point: allowing businesses to handle all of the administrative aspects of their patent application, such as keeping track of deadlines and paying fees, calling on her expertise in patent law and document writing only when necessary. After 5 years at Mewburn Ellis, she went solo.
Realizing that establishing a portfolio of clients would take time, Hillis secured freelance work to supplement her income as she established her company. She worked with a patent law firm called ipconsult , whose business model meshed well with that of her new company. "We bring together several sets of experts as and when needed in a virtual environment, so Kate's company is a perfect fit to complement what we do," writes ipconsult founder and patent attorney Neville Walker in an e-mail to Science Careers.
Hillis cautions that patent attorneys with dreams of setting up their own company need to be prepared for "hard work, disappointments, and to not earn very much initially." But the eventual payoff offsets these disadvantages, Hillis says. She enjoys flexible working hours and managing her own workload. But the main advantage of working as a sole practitioner is the opportunity to delve into the nuts and bolts of an invention. "The work is fundamentally the same whether you work for a large firm or on your own, but the clients are different," she says. "My work is mostly with U.K.-based small businesses and individuals, so I nearly always deal directly with the inventor."
Her most interesting and rewarding case to date involved patent applications for several inventions for removing explosive devices and protecting people working in minefields, she says. "These inventions were on the cutting edge of technology and were extremely worthy as well," from a human point of view. "Also, I found the inventors' enthusiasm about their inventions infectious," she says.
So, no regrets? Well, not many. "I sometimes miss the sense of tangible achievement that engineering can give. But patent law provides interesting intellectual challenges every day," she says. "My work spans the mechanical and electronics fields, and it is fascinating to get an insight into so many different new technologies."
• Inside Careers features a detailed list of vacant trainee positions  in the United Kingdom.
• The Chartered Institute of Patent Attorneys  runs seminars and events to help its members with their continuing professional development.
• The U.K. Intellectual Property Office 
• The European Patent Office 
• The Institute of Professional Representatives before the European Patent Office  gives guidance on the European qualifying examination.
• The IPKat  is a useful blog for keeping up to date with new legislation and the outcomes of legal cases about intellectual property.
Sarah Reed is a freelance science writer based in Cambridge, U.K.