Financial planners watch for a number of warning signs about potential clients:

Would-be Wall Street wizards who demand their financial planner to dole out hot stock tips and generate sky-high investment returns;

Detail-crazed engineers who get lost in the weeds of their investment portfolios;

Easy-come, easy-go types who have trouble making appointments or who would choose a financial planner based on how close the office is to their house.

These are just a few of the red flag flags financial planners look for when prospecting for clients and deciding whether to work with someone.

Potential clients in search of a financial planner may think the vetting is a one-way street, with advisors scrambling to sell them on their services.

But the vetting goes both ways, say financial planners with established practices. Planners say they think carefully about whether a potential prospect is the right fit and won't fritter away valuable time better spent on more cooperative and profitable clients.

"For me, the most important element is the answer to the question "is this person coachable?" said Michelle Buonincontri, a certified financial planner, or CFP, and a certified divorce financial analyst, or CDFA, in Anthem, Ariz. "If they're not, that's a big red flag that just leads to issues down the road. Past experience has taught me this."

Obsessed with market returns

When a potential prospect starts demanding outsized market returns or else, financial planners with busy practices more likely than not will start looking for the exits.

There are a couple reasons why this is such turnoff for planners. For starters, there is obviously no way to guarantee 20% portfolio returns -- that is unless you are cheating and pulling a Madoff.

But just as importantly, financial planners, especially the fee-only type, aren't interested in being stock jockeys, with hot-shot mutual fund managers and billionaire hedge-fund owners having a lock many times over on that corner of the market

Rather, they see themselves as financial quarterbacks, ready to guide clients through a myriad of financial challenges, from saving for retirement and figuring out how to pay for college for the kids to hooking them up the right attorney to do estate planning.

Prospects who want to spread their money around to different managers in hopes of getting the best return are a no-no for Kevin Reardon, a CFP at Shakespeare Wealth Management in Pewaukee, Wis.

"Our financial value proposition is in serving as your financial quarterback and handling all of your assets," Reardon said. "If the client wants to have multiple asset managers, they will get a lessor result and everyone involved will have more headaches, and as such, we choose not to work with them."

When screening clients, Eric Walters, president and founder of SilverCrest Wealth Planning in the Denver area, keeps a lookout for signs that investment returns are the main interest, not financial planning.

Prospects who expect he will be "picking the right stock" or "calling turns in the market" also ring warning bells for Walters, as well as behaving poorly towards staff.

Walters likes clients who "understand they are not the experts in certain areas and appreciate good, competent advice," and who are "loyal to their current advisors who provide them with good service and advice."

To smoke out unrealistic expectations, some advisors will ask a variation of the old question, "Where do you see yourself in five years?"

Mark Smith, president of Vision Wealth Planning, LLC in Virginia, will ask prospects this: "If work together over the next 3 years, what would need to happen in that time for you to feel our work has been successful?"

Then Smith, a CFP, will ask the opposite: "What are things that would make you feel unsatisfied?"

"Listening to the answers and asking follow up questions can go a long way to understanding mindset," Smith said.

For James Reardon, a CFP in Topeka, Kan., the question goes like this: It's a year from now, and we have done a good job for you, -- in your own words -- what is it that we will have done?

Reardon's most "troublesome prospects/clients by far, have engineering degrees."

Not engaged enough

It's not just prospects who want hourly updates on their portfolios who send financial planners running in the other direction.

Potential clients who are blasé about working with a financial planner or will only do it on their terms are also seen by some planners are bad bets.

Marla Mason, a CFP and wealth manager at A&I Financial Services in Englewood, Col., said clients who insist they can only meet on the weekends or in the evening, at their location, give her pause.

Excluding health or transportation issues, for Mason, it raises questions about how seriously the prospect views financial planners as opposed to doctors, dentists, lawyers and other professionals.

"This may mean that they don't ascribe the same importance to meeting with a financial planner as they do to other professionals like their doctor, dentist, CPA, or attorney who typically do not make house calls or take after hours appointments," Mason said.

Thomas I. Rindahl, a CFP and financial advisor at TruWest Wealth Management Services in Arizona, said his warning signs went off recently when he met with a prospect seeking a new advisor.

When he asked why she wanted to change advisors, the prospect said it didn't have anything to do with the previous advisor's performance. Rather, she had moved to a different part of town and didn't want to make the extra drive.

"The only thing communicated was a lack of connection to the old advisor and no real desire to connect to a new advisor. A relationship with an advisor was not a priority," Rindahl said.

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