Okay - first putting on accountant's hat. You can't shred the slips for at least 3 years after the sale - not because of chargebacks, but because of IRS! Most records for a business you should keep a minimum of 7 years. Yes, I know, all that paperwork takes up a lot of space, but you'll be glad you had it if you ever get audited. You should see all the paperwork we have for the store, SHEESH!
As Stan said, keep the slips in a locked cash box or someplace secure at the show (be sure you keep any extra copies and shred them immediately) and then file them by month. You can put them in a manilla envelope and put them in a file cabinet. More about the credit card slips further down in this post.
:: Taking off accountant's hat ::
Knucklebusters are a pain - they are bulky, the slide often doesn't apply enough pressure to imprint the card number/expiration date properly, and just overall aren't easy to use. We've had one for years and have probably used it less than a half dozen times - usually when the power went out. If you can't read the number and the expiration date, it could cause problems for settlement. If you use a knucklebuster, be sure that you can read the numbers on your copy of the slip - match it with the card while it's still in your hand! You have to be careful to destroy any carbon paper and extra copies. I'd suggest a good crosscut shredder!
In the flea market, we had a card reader that was battery operated and wireless (we could run it on electricity, also - we used it in the store for a while, but connected it to a hard wired phone line). It had a little antenna that we attached when setting up in the morning. We could swipe cards and do PIN entry all on one unit, so we didn't have to worry about extra cords or devices. It connected instantly to the card processor with each transaction and we didn't have to worry about being sure we manually phoned in or processed all of the slips at the end of the day. We could take debit and credit cards, which surprised many people. I still joke that we take debit and credit cards and we also take cash with 2 co-signers and 3 IDs. My personal advice is to get a wireless card reader/pinpad with the best security encryption you can afford. We did pay extra for the wireless feature, but considering that it was essentially it's own cell phone, the fee wasn't too bad. The whole thing was practically idiot-proof and paid for itself several times over.
Debit cards usually cost a certain rate and credit cards usually cost a different rate. If the purchase is less than $20, it's usually better to run it as a charge, rather than a debit, but I ALWAYS give the customer the choice of debit or credit.
Fraud and ID problems - this comes from our neighborhood network meetings, most of them from the regional head of security at our bank.
Credit cards first - Using a credit card or the credit function of a bank card (with a VISA or MC logo) is the most secure for yourself AND for the customer - a signed receipt (whether from the card reader or the knucklebuster) is better protection for both of you.
When you get a card, look at the front, including the name and the expiration date. Then look at the back. See if the signature matches the name on the front. Some cards have the last 4 numbers of the card on the back of the card next to the CV number. (The CV is the number that you use to validate a card purchase.)
If you're doing a show or flea market where you have different and transient customers, ALWAYS ask for ID! I don't ask my regular customers for ID unless I haven't seen them in a while, then I joke about asking them because they could have an evil twin who stole their card.
When you look on the back of the card, you will see one of 3 things. One will be an unsigned card. When you ask about it, they'll say," I never sign my card" For them that is a BAD thing. An unsigned card voids the agreement with the card company and if it's stolen will have a terrible time getting things fixed. A merchant NEVER *has* to accept an unsigned card and at Christmas a couple of years ago MC and VISA told their merchants NOT to accept an unsigned card.
The second thing you'll see is a signature - when you ask for ID, you can compare the signature, but it's not an absolute. A signature on a fake ID will match a signature on a fake (or sometimes stolen) card. You also want to match signatures on the card with the signature on the receipt.
The third thing you'll see is "Ask for ID", "CID" or "Photo ID Required". NONE of these is acceptable unless the card is also signed. I know - we've all heard "don't sign your card, just put 'ask for ID' on it". Sign your card AND write "Ask for ID" on it. I wish I had a nickel for every time I've had the discussion with a customer about credit cards, IDs and signatures.
Now for ID's - ALWAYS ask them to take it out of their wallet and hand you the ID. Don't just look at the photo and say, "yeah, it's you". I tell people that if the picture on their ID looks like them, it's a fake! Think about it - your driver's license photo resembles you for about 10 minutes after the photo is taken! Look at the photo AND look at the information - there's a reason it's on the card - for IDENTIFICATION! Some states have a magnetic strip on the back with the info encoded. Others carry some of the info from the front of the card to the back - expiration date, issue date, date of birth, name, card number, etc. Look at the back of the card as well as the front - see if the info from the front matches the back. If someone is using a stolen ID, they will usually change the photo and maybe the name/address info on the front, but usually never bother to change anything on the back. The mismatch is where you will catch fraud.
The TSA at airports got in big trouble because they weren't catching altered ID's because all they were doing is looking at the photo, which of course resembled the person. There was a huge case in AZ - a guy used an altered ID and stolen credit cards for months and ran up about $250K in charges, until a teller at a bank realized that the young man at her window did not match the name and information for an elderly woman! Until that point, when checking ID, the clerks only looked at the photo and let it go.
While we're talking about fraud - think about counterfeit money. Those pens are nice if the bill's just been copied on a photo copier. If the bill has been "washed", the pen will show that it's a real bill. Older bills are problematic. New bills are better - there are lots of safeguards. Things like the security strip with the denomination on it (each denomination has the strip in a different place). Check the watermark (hold the bill to the light and to the right of the portrait, you will see a watermark of the same portrait. If you see Andrew Jackson where Ben Franklin should be, you have a fake bill! On the front of bills $10 and higher, the number of the denomination will color shift with the angle of the bill. Also, the bill is micro printed with the number on the back. There's much more to confirming whether a bill is counterfeit - take some time to visit your bank and as the personal banker to help you. If you get a counterfeit bill and turn it in, you will NOT be reimbursed for the funds. This is not fair, but that's the way it is. If someone tries to pass a counterfeit bill, call the police and if possible, don't let them leave. If they leave, get a description of them, their vehicle, including license plate, etc.
Our current card processor has the highest level of encryption. One of the nice features is that it shows the last 4 digits of the card number. Matching them with those numbers is one thing for preventing card fraud. We sometimes have a customer who will pay for a purchase, then decide she wants some other things. If the card is run more than once, the machine warns that it's a duplicate card number. This is sometimes annoying when the customer never stepped away from the counter, but if the customer dropped the card and someone found it and tried to use it, it would alert you that something might be going on.
When we process a card, we have 2 copies of receipts from the machine. The customer gets their copy stapled to their sales invoice and I staple our merchant copy to our copy of the invoice. (Makes for a big stack of papers at the end of the day or month, but it keeps everything together.) SO - for the answer of what to do with the slips - I would use a receipt book and then staple the merchant copy to my copy of the receipt and put both in that locked cash box or somehow secure them. Leaving them in the receipt book can get bulky. If you want to get fancy, you can have NCR invoices printed fairly cheaply. Either way, you have the information of what was purchased, as well as your copy of the receipt all in one place. Makes it easy if there is a question in the future.
I know I'm forgetting something, so PLEASE ask questions!
Deb