If you are having a clear-out and want to make some money selling old CDs, books or last season’s winter coat there is only one way to do it — via eBay, right? That’s the assumed wisdom and with four million users listing at least one item for sale on the online auction site each month, eBay dominates the market for the sale of unwanted items.

It isn’t, however, the only option, as a growing range of easy to use “trade-in websites” will pay you for your cast-offs. These offer the benefits of speed and convenience and are worth a look if the auction process intimidates you or you want to make money fast. You might earn more selling items individually on eBay, thanks to the auction process, during which prices are, if all goes to plan, bid up, but what price you achieve is uncertain until the auction closes. Most trade-in sites offer instant quotes so that you have an immediate idea of how much you will make.

WeBuyBooks.co.uk, Ziffit.com and Momox.co.uk take books, CDs, DVDs and games. MusicMagpie.co.uk and CeX buy CDs, DVDs, computer games and electronic goods, including mobile phones. Zapper.co.uk does the same, plus buys books too. Amazon has a “Trade-In” service for books, games and consoles.

Popular designer fashion resale sites include Vestiairecollective.com, Hardlyeverwornit.com, Covetique.com and Buymywardrobe.com.

Unless you’ve got something special to sell don’t expect to make a fortune. You will generally get about £1 for CDs, £1.50 for DVDs and £15 for computer games, says the consumer website MoneySavingExpert.com. Tara Evans, website’s consumer expert, says: “It’s always worth checking more than one website before you commit because prices vary and, unlike eBay, they give you a fixed amount.”

The sites can be picky about what they accept. This is because they make money either by reselling the items, or taking a commission after facilitating a sale directly to a buyer, and know what is and isn’t in demand. Once again, though, that removes the uncertainty from the selling process; if you have ever failed to attract any bidders during an auction on eBay you will know how dispiriting that can be.

How do they work?

Most work in a similar way; you type in an item’s barcode, ISBN or product name — some websites have apps that allow you to scan the barcode — and you will be offered an instant price. To complete a trade some sites insist on a minimum number of items or minimum overall value, so you may need to sell a number of items at the same time.

Others, such as the designer fashion resale sites, require you to jump through slightly more hoops, though you do have more control over the price. You submit a description, mentioning any imperfections, photos and set a price and you will be told whether the item will be accepted and when a buyer accepts the offer. For luxury items, you may be asked for proof of purchase; this is to ensure they are in tip-top condition and to protect against the sale of fake goods.

Once you are happy you accept the offer and send the items to a specified address; most will cover the cost of postage, offering a free courier service or a freepost label.

Unlike eBay, you do not have to set up a PayPal account to sell and get paid on these sites. There is usually the option to be paid by bank transfer or cheque — the technology-focused CeX even offers payment by Bitcoins. Amazon’s Trade-In service is more restrictive, paying you with an Amazon gift card. You should receive payment within a week.

Are prices guaranteed?

No, and a look at review websites such as Trustpilot.co.uk reveals that when there is a big difference between the price quoted and the price paid this can cause frustration. Anything you send in to sell will be checked for quality; CDs for scratches and a full set of sleeve notes, books for damage such as missing or torn pages, textbooks for tests partly or fully completed. If your items fail the quality test then you will get a lower price than that quoted or they might even be rejected as faulty, so check the terms and conditions before you post anything.

Fanny Moizant, co-founder of Vestiaire Collective, says: “Before a sale is completed items are sent to our headquarters in Paris [postage is free] where they are manually checked by experts. If we find there is a difference between the description made by the seller and the item we will suggest the price is reduced and validate that with the buyer and seller before shipping the item to the buyer. We will cancel the sale if it is too different to the description, refunding the buyer and shipping it back to the seller.”

Too much hard work?

Some of the fashion sites offer a VIP service. Rather than having to do the work yourself they collect items from you, or even send a representative to select items from your wardrobe, and photograph, list and sell them for you. You will pay a higher commission for the service.

Sarah Jagger, a make-up artist and fashion blogger at Sarahjagger.com, has been using Vestiaire Collective’s concierge service for several months. She says: “They send a courier who picks up everything I want to clear out and Vestiaire checks they are in a good condition and sets the prices, which I then approve. It means that I am not constantly going backwards and forwards to the post office every time I want to sell.”

She adds: “It is a nice way to recycle things. As someone who is really busy and travels alot I find myself killing time in airports so I end up running into Zara and spending money on things I don’t really need. This way I can go onto the app and sell things I don’t need and buy something I really want.”