What you need before you start
Setting up an online payment system means choosing a processor, connecting it to your bank account, and configuring it to accept payments on your website or app. You will need a business bank account, a tax ID or Social Security number, and basic information about what you sell and how much you expect to process monthly. Most processors also require you to read and sign their merchant agreement, which spells out their fees and what they will and will not let you sell.
The order matters: pick your processor first, then integrate it into your website or point-of-sale system, then test it with real transactions before going live. Skipping the test step is how most businesses discover problems after customers have already tried to pay.
You do not need a separate merchant account from your bank anymore—most modern processors handle that part for you. But you do need to know your monthly sales volume and the average transaction size, because different processors charge different rates depending on those numbers.
Key Takeaways
- You will need a business bank account, tax ID, and your processor's merchant agreement signed before you can accept payments.
- Different processors charge different rates based on your sales volume and transaction type, so comparing three options before you choose saves money over time.
- Integration means connecting your processor's code to your website or app, which usually takes a developer a few hours if you do not do it yourself.
- Testing with real small transactions before you go live catches problems that would otherwise frustrate your first customers.
- Fraud protection and dispute handling vary by processor, so read what happens when a customer claims they did not authorize a charge.
Choosing between payment processors and what they cost
A payment processor is the company that moves money from your customer's card or bank account to your business account. Stripe, Square, PayPal, Authorize.net, and Adyen are the largest, but hundreds of smaller ones exist. Each charges a percentage of each transaction (usually 2 to 3 percent), a flat fee per transaction (usually 20 to 30 cents), or both. Some add monthly fees for features like invoicing or recurring billing.
The processor you choose depends on what you sell and how you sell it. If you run a physical store, Square or Clover work well because they handle in-person cards and online payments from one dashboard. If you sell only online, Stripe or PayPal are simpler because they do not require hardware. If you send invoices and wait for payment, Authorize.net or Stripe's invoicing feature might fit better.
Get the pricing page for at least three processors and calculate what you would actually pay on your expected monthly volume. A processor that charges 2.9 percent plus 30 cents per transaction costs you differently if you process one hundred $50 orders versus ten $500 orders. Write down the total fee for your realistic scenario, not just the percentage.
Setting up your merchant account and bank connection
Once you have chosen a processor, you will create an account on their website or app. They will ask for your business name, address, tax ID, and the bank account where you want deposits to land. That bank account must be in your business name—personal accounts create delays and can get frozen.
The processor will verify your identity and your bank account by depositing two small amounts (usually under $1 each) into your account and asking you to confirm the exact amounts. This takes one to three business days. Do not skip this step or ignore the verification email—your account will not process real payments until it is complete.
Some processors also ask for a voided check, a business license, or a photo of your ID. Have these ready before you start the signup, because delays in providing them can push back your launch date by a week or more. Read the processor's requirements page all the way through before you begin.
Integrating the processor into your website or app
Integration means connecting your processor's payment form to your website so customers can actually pay you. If you use a website builder like Shopify, Wix, or Square Online, the processor is usually built in—you just flip a switch and connect your account. If you built your site with custom code or use a platform like WordPress, you will need to add code that the processor provides.
Most processors give you two options: a hosted payment page (where customers leave your site to enter their card details) or an embedded form (where they enter details on your site itself). Embedded forms keep customers on your site and usually convert better, but they require more technical setup. Hosted pages are simpler but feel less integrated.
If you do not code, hire a developer to do this step. It usually takes two to four hours. Ask the processor for their integration guide and give it to the developer—it will tell them exactly what code to add and how to test it. Do not let them start without reading it.
Testing before you accept real payments
Every processor gives you a test mode where you can send fake transactions without real money moving. Use it. Create a test customer account, run a $1 transaction, and watch it move from your test dashboard to your bank account (it will not actually deposit, but you will see it recorded). Check that your confirmation email goes out, that your inventory updates if you sell physical goods, and that the customer sees a receipt.
Test with a declined card too—most processors provide a test card number that always fails. Make sure your customer sees a clear error message and knows what to do next. Test a refund as well: process a small transaction, then refund it, and confirm the money comes back to the test card.
This step takes an hour and catches 90 percent of the problems that would otherwise hit your first real customers. It is the cheapest insurance you can buy.
Fraud protection and what happens when disputes arise
Every processor offers some fraud protection, but the level varies. Basic protection flags obviously fake transactions (mismatched addresses, impossible card details). Better protection uses machine learning to spot patterns. The best includes chargeback protection, which means the processor covers you if a customer claims they did not authorize a charge and their bank sides with them.
Read your processor's fraud policy before you go live. Find out what they do if a customer disputes a charge, how long you have to respond, and what evidence they need from you. Most want an order confirmation, a shipping receipt, or a delivery signature. If you sell digital goods with no shipping, ask them specifically how they handle those disputes—some processors are stricter with digital sales.
Keep records of every transaction: order details, customer email, IP address, and shipping address if applicable. If a dispute comes in, you will have 7 to 10 days to prove the customer authorized the charge. Having this information ready is the difference between winning and losing the dispute.
Deposits, timing, and when money actually hits your account
Your processor does not send you money every day. Most hold transactions for a settlement period (usually one to three business days) before depositing them to your bank account. Some processors also hold a percentage of your deposits in a reserve account for the first few months, releasing it slowly as they confirm you are not running a high-fraud operation.
Ask your processor about their settlement schedule before you sign up. If you need money fast, some offer next-day deposits for a higher fee. If you are just starting out, expect deposits to take three to five business days from the time a customer pays.
Your bank account will show the deposit as a lump sum, not individual transactions. If you need to see which customer paid which amount, you will have to log into your processor's dashboard—the bank statement alone will not tell you. Set up a system to match deposits to orders so you know which customers have paid and which have not.
Keeping your processor account secure
Your processor account is a target for fraud because it controls where customer money goes. Use a strong password (at least 16 characters, with numbers and symbols), enable two-factor authentication if the processor offers it, and do not share your login with anyone who does not absolutely need it.
If you have employees who need to process refunds or see transaction history, create separate accounts for them with limited permissions instead of sharing your main login. Most processors let you do this from a settings page.
Check your processor's dashboard at least weekly for transactions you do not recognize or deposits that went to the wrong account. If someone gains access to your account, they can change your bank details and steal future deposits. Catching it fast limits the damage.
Frequently Asked Questions
Do I need a separate merchant account from my bank?
No. Modern processors like Stripe and Square handle merchant accounts for you—you just connect your business bank account and they deposit money there. Your bank does not need to approve anything. This was different 10 years ago, but it is not anymore.
What if a customer's card is declined?
Your processor will send an error message to the customer explaining why (insufficient funds, expired card, fraud block, etc.). The customer can try a different card or contact their bank. You will see the failed transaction in your dashboard but no money will move. You are not charged a fee for declined cards.
Can I accept payments without a website?
Yes. You can send invoices through your processor (Stripe, Square, and PayPal all offer this), and customers click a link to pay. You can also use a payment link—a unique URL you share with customers that takes them to a payment form. No website required.
How long does it take to go live?
If you use a website builder with the processor built in, you can be live in a few hours. If you need custom integration, add one to two weeks for a developer to build and test it. The verification step (confirming your bank account) takes one to three days no matter what, so plan for that.
What happens if my processor shuts down or goes out of business?
Your money in their system is protected—it goes to your bank account, not theirs. But you will need to switch to a new processor and update your website. This is rare with large processors but has happened with smaller ones. Choose a processor that has been in business for at least five years if stability matters to you.