Don't panic. Here are some steps you can take to report and replace your items and reduce your risk of fraud.
Some banks allow you to temporarily deactivate your card while you look for it. You can normally do this through online or mobile banking.
This prevents fraudsters from spending your money. If you find your card, you can reactivate it through your online account.
Before you take any further action, think about where you last had your wallet or purse to figure out where it could be. You may have dropped it or left it behind, so check your:
Pockets
Bags
Car
Desks
Lockers
Also think about where you've been and call any public places you've visited to check if it has been found or handed in.
If you can't find your purse or wallet, call your bank, building society or credit card provider (or card issuer, such as Visa or Mastercard) as soon as possible to:
Report your cards as lost or stolen: These will be permanently deactivated immediately and new ones can be ordered.  Replacement cards usually arrive within three to seven working days.
Check your statement: If you don't recognise any of the transactions tell your bank. They can open a fraud case and credit your account with the lost amount while they investigate.
Report your cards missing as soon as possible. Your bank could deny you a refund and hold you liable for spends carried out by a thief if you leave it too long.
Keep a close eye on your accounts so you can identify and report suspicious activity straight away.
This will help you figure out what you need to replace and which organisations you need to contact.
Driving licence
ID cards
Credit and debit cards
Gift cards and vouchers
Membership cards
Loyalty cards
Contact the companies to explain and replace your items. You can do this:
Online
By phone
By visiting a local branch
If you keep you house key in your purse or wallet, consider changing the locks to reduce the risk of a robbery. Thieves have been known to:
Note down your address from your driving licence
Make a copy of your key
Hand the wallet into a police station
You might have your key back, but the criminals have one too, giving them perfect access to burgle your house.
If you think your purse or wallet has been stolen, report it to the police. You may not think this is necessary as the police are unlikely to open an investigation into its disappearance.
However, a crime reference number is useful if you become a victim of identity fraud because of losing your purse or wallet.
When doing this, you may be asked:
A description of the wallet or purse
When and where you lost it
What was inside it
Other details about the circumstances e.g., potential suspects
You can read more on how to report your stolen purse or wallet on theÂ
Keep an eye on your credit file to ensure your details have not been used fraudulently to make credit applications in your name. Your file can be obtained from one of the UK's three credit reference agencies:
If you spot anything out of the ordinary, notify the agency that you're using, so they can look into rectifying it.
After you've taken the relevant steps, replace your wallet or purse with a new one. Think twice about what you need to carry so you don't lose everything if it happens again.
To make losing your purse or wallet easier to deal with in the future, you can:
Carry less: Ask yourself if you need to have every single card with you. Also avoid storing sensitive data that can make you a target e.g., passwords and addresses.
Scan what's in your wallet: Store images of your wallet contents in a password-protected file to help identify what needs replacing. Or, download a "lost wallet" app instead.
Get insurance: Some companies insure cards and cash as an optional extra of contents insurance. Levels vary, but policies are available that cover cash to £500 or £750, and credit cards to £1,000.
Spending with a credit card offers extra protection from scammers and fraudsters with Section 75 cover. Compare credit cards to find one that suits how you spend.
Salman is our personal finance editor with over 10 years’ experience as a journalist. He has previously written for Finder and regularly provides his expert view on financial and consumer spending issues for local and national press.