3. Clothes calls

What you wear to work will also tap your budget. Need to dress for success? A high-quality suit is going to cost at least $800, possibly more, depending on the designer and where you buy it.

Dress shoes will cost around $100 a pair (or much more, depending on the maker, style and quality). A nice blouse, a leather belt, a handbag, messenger bag, laptop case, raincoat, snow boots and umbrella are just a sample of the clothing or accessories you may need for an office wardrobe.

4. Eating away at your savings

Lunch and snacks will also have you reaching for your wallet throughout the day. If you shell out $10 a day for lunch, and an additional $5 a day for coffee or snacks, you can deduct nearly $4,000 from your take-home pay.

Tired after a long day at work? Rather than making an affordable home-cooked meal, you will likely spend $10 or more grabbing fast food on the way home at least two or three times a week.

Socializing after work is important for fostering teamwork and morale. But even a lone beer and a single appetizer once a week can subtract about $20 or so from your ever-dwindling paycheck.

5. Charity fatigue

The workplace also makes you a target for charitable pleas. It is hard to deny co-workers when they ask you to support their kids by buying Girl Scout cookies or magazine subscriptions. There are also walk-a-thons, road races and other charity-minded endeavors for which co-workers will pass the hat.

Gus from accounting is retiring? A cake for Carol's birthday? Helen from HR just had a baby? Choosing not to chip in is a cardinal sin in the realm of office politics.

How to cut back

Every work-related expense you can reduce is like getting a raise. Every dollar saved is one that can go to other household expenses, or be redirected to savings or a retirement plan.

Finding ways to save money each work day can be fairly simple. Pack a lunch each day instead of running to the local sub shop and try to prepare (and possibly freeze) some meals you can heat up once you get home on those days you are too wiped out to play chef. Using a slow cooker with a timer is another way to have a hot meal ready for you by the time you pull into the driveway.

Instead of paying $100 for a shirt at Brooks Brothers, avoid the boutique shops and malls and instead stock up with shirts, ties, blouses and dresses at more affordable retailers such as Kohl's, Target or even Wal-Mart. The savings can be huge, and odds are most co-workers won't even notice.

One way to reduce the costs of commuting or day care is to see if your employer is open to you telecommuting one or two days a week.

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Your human resources department can also help you realize savings through pretax payroll deductions for such necessary costs as transit passes. Your company may also offer a dependent care reimbursement account.

These plans, similar to a health savings account or flexible spending account, allow you to make pretax payroll deductions to defray the cost of day care for children under the age of 13 (as well as adult day care for the disabled or infirm). Some can be used to reimburse for eligible daycare expenses for children age 12 and under or for adult day care expenses for a disabled spouse or IRS-qualified tax dependent.

The maximum annual deduction is $5,000 for a married couple.

This article was reported by Joe Mont for TheStreet.