Valentine's Day 2006 has been chosen as the cut-off point for consumers with a chip and pin card who forget their number and try to pay for their goods by writing their name on a slip.
Today, you can still admit to a memory lapse and sign. But from 14 February, retailers - wary of fraudsters with stolen or counterfeit cards - will no longer guarantee to let you take your goods home if you forget your security code at the till.
The decision last week by the Association for Payment Clearing Services (Apacs), the body responsible for payments between banks and retailers, is intended to crack down harder on card theft and fraud.
Chip and pin is already having a big effect: in the first six months of this year, counterfeit and stolen card crime fell by nearly a third to £89m, compared with the same period last year. But Apacs wants swifter results. In France, the introduction of the chip and pin scheme in the 1990s reduced card crime by as much as 80 per cent over a couple of years.
However, in the UK, not everyone has the new technology yet. Of 67 million debit cards, some 61.7 million now contain a chip - 92 per cent. But of 71 million credit cards, only 55.5 million have a chip - 78 per cent.
Over the next three and a half months, banks and other lenders will be working hard to try to get every wallet stuffed with chip and pin cards.
If you don't have one by 14 February, you will still be able to sign for goods in the traditional way, but nearly all of us should have chip and pin by then. However, question marks may remain for many cardholders. Here is a rundown of what you need to know.
Why all this Valentine's Day fuss? We're already in the chip and pin era.
We are, but too many of us still forget our pins at the checkout.
On 1 January this year, liability for fraud switched from card providers to stores, so spurring retailers to adopt chip cards and machines. Since that date, shoppers whose minds go blank have still been able to pay by signature. But this is now to end, since levels of fraud are still too high for the retailers.
So is this really the death of the signature at the checkout?
Not technically, but tens of millions of customers who have signed for goods for years will no longer be able to do so.
The signature will still have a place - for example, among the disabled who cannot use the new technology; they will pay using "chip and signature" cards. And if you're one of the few still without a chip and pin card on 14 February, you'll be able to carry on as before until you get the new plastic.
Those outlets, including small stores and restaurants, that don't have chip and pin now and probably won't in the future will also accept your autograph. Abroad, you'll find many countries that don't yet have the technology.
And if you regularly use a local store that has a chip card machine, and are on good terms with the proprietor or manager, it's unlikely that you'll be refused your goods if you forget your pin after 14 February. The new rule is simply to protect retailers from fraudsters unknown to them.
Will the liability for losses change on 14 February?
No. Liability for losses remains the same: with banks and retailers, and not you.
The bottom line is that any retailer accepting a signature after this date will bear the financial loss for any fraud committed.
Having so many cards, I keep forgetting my pin number. Any tips?
Don't go for anything obvious that a thief could link to you if he stole a bag containing your wallet and other personal effects - for example, a birthday highlighted in a diary.
If you have a handful of cards, Jemma Smith, spokeswoman for Apacs, suggests you use the same pin for all your accounts.
As long as you keep it secret, there won't be a problem.
What if I absolutely have to write the pin down and keep it in my purse?
If your card is stolen or counterfeited and used fraudulently, it's likely you'll be seen as negligent and held liable for losses.
I've forgotten my pin.
To get your pin reissued, contact your card provider, which will send a new one in the post. Change this to something more memorable at a cashpoint.
Rumours persist that, to protect against fraud, some shops won't accept a card that hasn't been enabled with chip and pin. Is this true?
No, says Ms Smith at Apacs: "Retailers have no reason not to accept them."
Will every shop have chip and pin?
Probably not. To date, 750,000 out of a total of 900,000 retail terminals in the UK are set up to accept chip and pin.