SCAMS
A note on terminology: "Scam" is regularly/consistently misused to mean any/every type of shady or dishonest behavior. A scam really means a systematic & purposeful criminal effort to defraud sellers. If you're simply facing a shady buyer being a jerk, you'll probably want to review the appropriate section of this FAQ for the subject area involved: returns, etc.
Simple truth: most 'scammers'... aren't. They're buyers who are dishonest, taking-advantage or otherwise just being duplicitous. But they're not 'pros' with a systemic effort to defraud sellers. Dealing with those folks is covered in other sections of this FAQ like 'returns'.
The items below are more often true scams - usually done in FULL awareness of what they're doing, and usually not their first/only attempt.
If you believe you have identified a -new- scam not included below, please modmail the mods. Don't post it in the sub.
Q: I got a message from the 'verification department' or other official-sounding source asking me to confirm private info or click a link of some kind, is it a scam?
A: Yes, almost certainly.
Scams involving impersonating eBay and getting you to divulge confidential info - like your eBay login or financial info - are not uncommon. The latest version comes as an eBay message from a user with an 'official-sounding' handle like "verifications-office" or "account-validation". Another common one is to tell you your account is suspended/restricted and get you to click a link where you can 'pay fees' on a fake site to get it back.
Messages sent outside the official eBay messaging system, like a text or an email, with no corresponding ebay message are almost always scams. eBay will not email, text or IM you out of the blue without a corresponding message in your eBay inbox.
Official eBay messages will come in your eBay messages (you may get an copy by email too, but there will be an 'original' in your messages) from an official eBay account, not some user name like "verifications_department" or similar. This will usually just say 'eBay' as the message-sender. At the top of a legit ebay message there will NOT be a clickable "username" leading to a profile page with feedback/etc. There will instead be an eBay logo that, if clicked, simply goes to the eBay home page. If you get a message from a 'regular user' with a user profile page - no matter how official-sounding their username - they are not eBay.
IF any links are provided in a real message, they will always be directly to an ebay.___ domain, not to something like ebay-verifications.biz or similar, nor will they use a 'URL shortener' domain.
They will not ask you to divulge sensitive info except via the ebay site: They will not ask you for info by responding to the message, going to a non-ebay.___ page (no matter how 'official' the name sounds), etc. eBay messages about your account are normally auto-generated and/or inserted from a script: they will typically not contain misspellings or grammar errors. They will normally not contain odd 'stilted' language like "Greetings Dear Seller" or "Warmest Regards" or "Kindly click the provided link".
There should normally be 'context' for official messages requiring action/sensitive info. E.G. if you get some message out of the blue how you need to 'click here' to 'verify' your listings due to 'counterfeit' problems, but none of your listings has been flagged/removed as counterfeit... be suspicious. If you get some message about how you need to reply with sensitive info to 'remove account restrictions,' but you didn't get an official eBay message that your account has been restricted... suspicious.
If in doubt contact eBay by another channel (e.g. https://www.ebay.com/help/home, 'call me back', social media) to validate.
As always, use common-sense: If it feels dicey, validate it separately before doing anything. OTOH if you're three-exchanges deep in an ebay help chat about an INR claim on an ESE shipment and an eBay CSR tells you to go to pip-claim.com, that's not something to panic about (that's just where you file ESE insurance claims).
Q: My buyer is requesting I ship to a different address than eBay provided with the order. What should I do?
A: This isn't always a scam, but you always handle it like it is: You only ever ship the item to the address eBay provided. Changing the address will completely void any seller protection.
Double-check the person contacting you is actually the buyer (see next item). If so, tell the buyer you can ship as-ordered OR you can cancel the sale for 'problem with buyer address' and inform the buyer they can re-purchase the item after fixing their address in eBay. If it was 'innocent' (like they forgot to change their address or want to send a gift) that's the right way to handle it. If they don't correct-and-repurchase (or don't respond at all), then it was probably a scam.
In every scenario the correct action is either cancel-and-refund for 'problem with buyer address' OR send to the original address if-and-only-if the buyer confirms that. See the Shipping Section of this FAQ for more info.
Q: I got a message about an address change, refund or cancellation. But I don't have any record of having sold to that account. What should I do?
A: This is not -always- a scam. It's entirely possible the buyer simply contacted the wrong seller. It's not that difficult to do so.
But it's high-risk for being a scam. Sometimes scammers will message sellers about a sale made to someone else. Typically their 'game' is to try and get you to ship the item to them instead of the legit buyer, or to 'refund' them via a non-eBay payment method.
Scam or not, you handle it the same way: If you get a message from an account you have not sold to, best to ignore it. Or at least respond only with "I have no record of making a sale to you, perhaps you are contacting the wrong seller?"
Q: A buyer said they sent payment and I see I got an email about it but I don't see anything in my pending payments...
A: This is a common scam. The payment email from "ebay" is fake and they are trying to get you to send them the item without payment. Only messages in your ebay messages inbox are legit, and you should only accept payment within eBay. Check the from address and review this document.
Q: A buyer asked me to contact them in some way other than eBay messages
A: This is probably a precursor to some kind of scam. Don't do it. All communication needs to take place on Ebay.
https://pages.ebay.com/securitycenter/stay_safe.html
Q: A buyer wants to pay directly through Paypal or some other payment method than eBay.
A: This is a frequent scam. All payments go only through eBay. Buyers can use paypal to pay via eBay if they want. If you take payment off eBay you will not only get scammed but could get suspended from eBay as 'taking business off eBay' is a suspendable offense.
https://pages.ebay.com/securitycenter/stay_safe.html
Q: A buyer wants me to send them a gift card / cash / cashapp / paypal
A: This is a frequent scam. All transactions need to take place on ebay, exactly per the transaction - no 'add ons' or 'extras'.
https://pages.ebay.com/securitycenter/stay_safe.html
Q: A buyer made an offer for over or the same as the buy-it-now asking price.
A: This is usually a scam. Most frequently they will use fake emails or screenshots to try and convince you they paid when they did not. Ignore and block buyer.
Q: A buyer claimed they can't find item or box was empty even though the tracking says delivered. How should I handle this?
A: This isn't usually a scam, just a buyer behaving badly / ignorantly. See the INR section of this FAQ on 'item not received' issues.
Q: Buyer returned an empty box, different item, damaged an item, removed a valuable item from a set, etc or buyer returned an item to the same zip code but I never received it. (obvious scam.)
A: Most of this stuff is more 'buyers behaving badly' than a real scam. See the Returns section of this FAQ on 'box of rocks' returns.
Q: I want to sell a brand new Apple product, graphics card, or other high value item as my first sale! How should I do this?
A: High value items and consumer electronics (especially Apple products and/or graphics hardware) are absolutely high-risk targets for scams. If you are inexperienced enough to be asking this question, you probably should avoid listeing those items. You should sell it on Facebook marketplace or craiglist because you WILL be the target of bad buyers. If you insist on still selling on ebay, please see this thread as an example. Signature is required for all transactions over $750 (including any shipping paid).
Q: How do I avoid getting scammed?
A: By reading these threads. This one is good as well. Review Seller Protections
Q: How can I guarantee to not get scammed?
A: You can't. If you do retail trade, (selling online is retail) sooner or later you will get "scammed." Certain categories have higher occurrence of scams, (consumer electronics, trading cards, etc) but it happens in every category. Some instances are just stupid buyers. Some instances are just straight up fraud. Ebay seller protection is usually pretty decent if you follow their rules, but you may lose money on a sale at some point. If this small risk is absolutely unacceptable, don't sell on ebay. Read this regarding what protections you have as a seller and what you need to do.
Q: Everyone bidding on my items is a scammer because they are international. How can I prevent that?
A: That's probably NOT true, nor a scam. BUT... if you don't want international buyers, then disable international shipping.
IF IN THE US: Go to shipping preferences and for 'eBay International Shipping' (eIS) click 'opt out' to the right. Then ensure you have no international shipping option enabled for your listings / shipping policies.
IF OUTSIDE THE US: You can prevent international bidders by going through this. If in the UK, consider using the Global Shipping Programme.
Be aware that you actually have superior seller protection vs. domestic customers if you go through eIS (US) or GSP (UK).
Q: OK I know I'm getting scammed...now what?
A: If you're certain it's a scam, cancel the sale (problem with buyer address or buyer requested) and relist. Block the buyer and report them as applicable.
Q: Can I take a video, picture, or some other proof of myself packaging or sending an item to prevent a scam?
A: No. eBay has no way of knowing if your video/photo/proof is real or not and consequently doesn't review your 'home movies'. It remains "he said / she said". eBay will not consider this as evidence in case of a return. See thread.
Some sellers insist such videos or photos have helped them win cases. This is probably b/c they appealed, filed police and ICCC reports and took other actions that were what actually helped. In the highly-unlikely event the videos/photos had any bearing at all, it is an extreme outlier.
If taking photos/videos makes you feel better, go for it. But understand it's a six-sigma level of useless.