There's no way around it: Where you open an IRA matters to your investment portfolio, and it affects more than the price you pay. Brokers offer different investment menus, research capabilities, and tools to help you plan for retirement. Today we're taking a look at how Capital One and Merrill Edge compare on key criteria for retirement investors.

Commission prices

Capital One and Merrill Edge offer the exact same pricing at their standard rates.

Brokerage

Stocks and ETFs

Stock Options

Mutual Funds

Merrill Edge

$6.95 per trade

$6.95 + $0.75 per contract

$19.95 per purchase

Capital One

$6.95 per trade

$6.95 + $0.75 per contract

$19.95 per purchase

Data source: company websites.

Having the same commission schedule doesn't mean that customers will ultimately pay the same amount, however. Keep in mind that both brokers offer ways to save. Capital One's ShareBuilder program can be used to make trades for just $3.95 each, as long as you don't mind waiting until the next Tuesday for the trade to process. Merrill Edge customers who maintain a minimum balance in their account (Bank of America accounts included) can receive up to 30 commission-free trades every month.

Beyond these money-saving opportunities, some brokers' special offers for IRAs include cash bonuses that top off your account with free money just for signing up. At any rate, with most trades starting at less than $7, neither broker will break the bank.

Mutual fund selection and commission-free choices

You won't find commission-free ETFs at either broker, but both offer no-load, not-transaction-fee mutual funds that you can buy or sell without paying a fee.

Brokerage

Total Mutual Funds

No-Load, No-Transaction-Fee Funds (NTF)

Commission-Free ETFs

Merrill Edge

More than 7,600

More than 2,300

Not available

Capital One

More than 1,100

More than 400

Not available

Data source: company websites and representatives.

Over time, fee-free fund choices can save you a fortune. At nearly $20 per purchase, an investor who made a bi-weekly investment in a mutual fund that didn't qualify for free trades would pay more than $500 in transaction fees at the standard price of $19.95. 

Minimum deposit requirement for IRAs

While there aren't many investments that you can make for just $1.00, you can open an account with that amount. Merrill Edge and Capital One offer no-minimum IRAs, which allow you to open an account without making a massive deposit on day one.

A pencil and calculator sitting on top of a ledger with numbers written on it.

Start building your portfolio from the ground up with a no-minimum IRA account. Image source: Getty Images.

International stocks and ADRs

Online brokers make it possible to invest in companies located all around the world, but there are a few limitations. Here's how Merrill Edge and Capital One compare for foreign investments. 

Type of Investment

Merrill Edge

Capital One

American depositary receipts (ADRs)

Yes

Yes

Stocks traded on international stock markets

No

No

Mutual funds and ETFs of foreign stocks

Yes

Yes

Data source: company websites and representatives.

The biggest limitation to each brokers' service is that they don't offer the ability to send trades to international stock exchanges. Thus, investors who want to invest overseas will have to invest in funds, or invest in companies with U.S. tickers. (To be fair, only a few brokers offer trading on international exchanges.)

Mobile app

Mobile phones and tablets enable you to trade from just about anywhere. Here's how each brokers' users and customers rated their mobile trading apps, as of Jan. 31, 2017:

Brokerage

Apple App Store

Google Play

Merrill Edge

2.0 stars

4.0 stars

Capital One

3.0 stars

3.0 stars

Data source: relevant app stores.

IRA fees: Maintenance and inactivity fees

Fees that may go unnoticed on large accounts can add up quickly on smaller account sizes. Keep on the lookout for two fees: maintenance fees (recurring charges for simply having an account) and inactivity fees (for trading too infrequently).

Merrill Edge and Capital One do not charge an annual maintenance fee or inactivity fee, so you won't have to go out of your way to avoid a service charge.

Research and retirement planning tools

We tend to think that it's beneficial to have a wide range of opinions at your fingertips. Most brokers provide a laundry list of research and retirement planning tools to help their clients make better investment decisions.

Merrill Edge offers access to research from Bank of America Merrill Lynch analysts, S&P Capital IQ, and Morningstar. It also offers a collection of retirement planning tools to see how your portfolio stands up against your retirement goals and timelines. 

Capital One's research center is powered by Morningstar data for easy comparison of individual stocks and funds. Its Fund Evaluator tool makes it easy to compare funds, and find lower-cost alternatives to the funds in your portfolio.

Best brokers for IRAs: Capital One vs. Merrill Edge

Both brokers offer something different that make them better for certain types of investors. Capital One's ShareBuilder program makes it very inexpensive to make recurring purchases of stocks and funds at a tiny commission of just $3.95 per trade. Merrill Edge offers a longer list of fee-free mutual funds, and may win over customers who already have an account with Bank of America.

Ultimately, it's really all about how each broker fits your specific needs. To be clear, The Motley Fool does not endorse any particular brokerage, but we can help you find one that is a good fit for you. Visit Fool.com's IRA Center to compare several brokers all on one page and see if you qualify for any special offers for opening a new account.

Jordan Wathen has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.