Money mistakes are like termites. They can work quietly behind the scenes, gnawing away at your wealth. You might even avoid any major consequences for years -- right up until you realize a comfortable retirement has slipped out of your reach.

In a survey from ING Direct, 30% of U.S. retirees say they don't have the same standard of living they enjoyed while working. Among those respondents who were still working, 24% expected to make a lifestyle change after leaving the workforce. And 64% of those pre-retirees said they'd need to find some other form of income in retirement, such as gig work, selling assets, or starting a small business.

Serious older man

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A leaner lifestyle plus a new line of work isn't anyone's vision of a perfect retirement. Make sure you're not headed in that direction by avoiding these five money mistakes that slowly wreck your retirement prospects.

1. Flying blind

Moving through your working years without a plan for retirement is a scary proposition for two reasons. First, time is valuable with respect to retirement planning. It's vastly easier to build wealth when you have time to benefit from compound earnings. Second, if you're relying on Social Security to take care of you in your senior years, you're going to be disappointed.

Social Security in its current form usually only replaces 40% of your income. Without a means of covering the other 60%, you'll have to make some pretty major adjustments just to keep a roof over your head.

You can't make up for lost time, but you can make a plan right now. If you're early in your working years, that plan could be as simple as maxing out your IRA contributions or increasing your 401(k) contributions every time you get a raise. If you are over 50, you could downsize to slash your living expenses and then start saving as much as possible.

2. Saving less than 15% of your income

Saving $50 or $100 monthly might be fine for your emergency fund, but it's not fine for your retirement account. You'll likely need $1 million or more to fund your retirement, and you won't reach that milestone with small monthly deposits. To put things in perspective, you can save $100 monthly for 30 years and you'll accumulate $122,709, assuming a 7% growth rate. That won't last long as your main source of retirement income.

Alternatively, you could save 15% of your $50,000 salary at the same growth rate. After 30 years, you'll have $767,000 -- or much more if you raise your contribution every time your pay increases. Commit to saving that 15% for the long haul. If you have fewer than 30 years before your target retirement date, increase that percentage to 20% or 25% to make up for lost time.

3. Refinancing your mortgage improperly

Refinancing your mortgage to consolidate debt might seem like a wise financial move. But if you refinance repeatedly without reducing the term of your loan, you're racking up lots of interest changes and pushing back your final payoff date.

In the early years, mortgage payments are mostly comprised of interest charges. Consider a 30-year, 4.5% home loan in the amount of $200,000. The first 12 payments on this mortgage will total $12,160.44. Nearly $9,000 of that represents interest charges. Only $3,226.45 in that first year pays down your debt balance.

Front-loaded interest isn't a bad thing when you see the loan through to the end. But if you refinance every five or 10 years, you are punting that big debt balance and increasing the likelihood of having a mortgage payment in your senior years. On the other hand, owning a home free and clear in retirement gives you options, like the ability to raise cash through a reverse mortgage or by downsizing.

Think twice before refinancing your mortgage with a 30-year term. If you have to relocate, consider a 15-year or 20-year mortgage to avoid resetting your payoff clock.

4. Living the high life

Unless you have a large stream of passive income, a lavish lifestyle in your working years translates to a leaner lifestyle in retirement. Spending on exotic vacations, fancy meals, and even expensive cars depletes your wealth and reduces what you could be saving in your retirement accounts. You'll also become accustomed to a lifestyle you can't support once your paycheck goes away.

That's not to say you can't go on vacation or buy a new car. But you could swap out the $10,000 vacation for a $2,000 road trip or trade in the luxury car for a reliable, mid-sized vehicle. Then, direct the money you've saved into your 401(k) by way of higher contributions. You'll be glad you made those choices when you can retire with money in the bank.

5. Assuming you can work forever

Think you can make up for not saving by working forever? Not so fast. A recent TDAmeritrade survey questioned 2,000 Americans aged 40 to 79 on their path to retirement. Among the retired respondents, half of them left the workforce sooner than they'd planned. Health issues prompted 38% to leave their jobs, and layoffs affected another 22%.

The takeaway? Your timeline for retirement is not entirely within your control. Save now so you have a fall-back plan.

Retirees say it too: save early and often

The TDAmeritade survey also asked retirees to share their top financial advice. They said to save earlier in life, invest earlier in life, and pay off debt as soon as possible.

I couldn't have said it better. Don't let money mistakes steer you off course. Stay focused and you can build the comfortable retirement you deserve.