First you are going to need to set-up a PayPal account or make sure your existing one is okay to use merchant services. You will need a few important bits of information to get you started:

Warning: Some customers in recent years, in particular those who have used eBay, have had a bad experience or two with Paypal and are put off using it to checkout.

When you have finished filling out your product details you can copy and paste the code for the button into your HTML page. Remember to take some great pictures and tell your buyers as much as you can about the things they need to.

In the UK the Office of Fair Trading has a set of ‘DSR’s - Distance Selling Regulations that sales that are not carried out face-to-face must comply with. One important point to note is the exchange of goods should take no more than 30 days. For a full PDF guide click here.

Don't forget to update your site when you have sold all of your stock. PayPal have stock options so you can't oversell. Make sure your shoppers don't get disappointed though and put a sold sign on your site or delete the entire thing.

You will need to apply for a suitable[1] online payment gateway, this service collects money securely from credit and debit cards around the world and sends them to your merchant.

If you accept credit and debit cards you will already have a merchant account; contact your provider and talk to them about adding an Internet Merchant Service (IMA) to your existing account. At a basic level this upgrade will allow payments to be sent to your bank from an online transaction.

You will need to plan how you intend to do stock control, sitting down and looking at suppliers lead times and your existing stock control database.

When you have all your products in Shopify you will need to connect all the services that allow transactions, connect your payment gateway to your IMA and link-up any stock control services you use.

One of the tricky areas to manage is what to do when you have sold an item, otherwise known as fulfilment. A medium sized business will need to look at how they manage picking tickets, storage for their stock, printing invoices, areas for packaging, who is coming to collect the post and at what time. Calculating P&P can be a bit of a dark art[4], the weight and size of a product can really help with UK shipping – you should look to be as accurate as possible here. International shipping is the really tricky one, if possible work closely with your logistics company to ensure the price you charge the customer is enough. This is a constantly evolving beast for those who grow their online sales. Some even choose to outsource this all to third parties such as Amazon.

As consumers we often don’t think much of getting a refund from a retailer, these transactions are called ‘chargebacks’ by the card companies and are monitored very closely. A chargeback is any transaction going from the retailer back to the customer, so this covers fraud, refunds, disputes and more. Retailers must have a very low rate of chargebacks, in some cases this is less than 1% of their annual turn over before they incur fines and charges from their merchant. We urge you to fully research the contracts of the companies you choose to work with.