Every year, there are an estimated 6 million households in the United States that send over a combined billion dollars abroad. Whether those funds are for family or friends, or to purchase international assets, it is often difficult to send large sums of money. With so many options available, people need to take into account the speed, support and cost of the various methods financial institutions provide for sending and receiving funds. The following are the top five best and most secure ways to send large sums of money abroad.

1. Bank-to-Bank Transfers

Some banks let people take money directly from one bank account and deliver it to a recipient's bank account. These types of transactions can be arranged online, over the phone or in person at the delivering bank. They may have a fee depending on the institution, and the account and routing numbers for both the sending and receiving banks are required. Some banks offer special remittance programs for transferring slightly smaller amounts. Bank of America, for example, has a program where funds can be sent to a total of 5,700 locations in the country of Mexico, free of charge. However, in cases such as these, it is important to look at the exchange rates, because although a fee might not be charged, the institution could be making money off of the transaction fee spread.

2. Wire Transfers

Additionally, it is possible to send large sums of money from one bank account to another through the use of a wire transfer. These types of transfers are initiated through a bank officer at the delivering bank who fills out the necessary forms.

Wire transfers, for the most part, have to be done in person. There is also a fee for this type of service, but wire transfers offer protection from both banks involved, making the fee worth it. For people residing in the U.S., wire transfers must be executed before 5 p.m. EST for the money to arrive the same day.

3. Automated Clearing House Transactions

Automated Clearing House (ACH) transactions are a simple alternative to wire transfers and bank-to-bank transfers. Similar to wire transfers and bank-to-bank transfers, these types of transactions are electronic but use a computer-based clearinghouse that acts as an intermediary to process the exchange of transactions. The Federal Reserve bank, for example, is the largest U.S. ACH operator, processing 60% of all ACH transactions. There are no fees for these types of transactions, but they do require both banks to be linked together. To do this, both parties need to follow bank-specific instructions.

4. Cash-to-Cash Transfers

If a person has a large sum of money in cash and needs to send it abroad, it is possible to use domestic, walk-in money transfer centers to transfer that money to an international money transfer center. Institutions such as Western Union, MoneyGram and Ria offer this type of service.

Physical cash is deposited in one of these money transfer centers. The domestic currency is converted to the currency of the destination country and can be picked up by the recipient at a participating money transfer center. In some countries, the money can be delivered to the recipient at a residential or commercial location.

5. Prepaid Debit Cards

There are some services that can send funds via a prepaid debit card. If this method is chosen to send a large sum of money, the sender can load a prepaid debit card with cash funds, and the receiver of the funds can withdraw them using the prepaid debit card. In some cases, the prepaid card can be used to make purchases just like with a normal debit card. However, there is normally an activation fee or monthly fee.