Following the cyber attack on their website, there are some basic precautions you can take if you're a TalkTalk customer.
TalkTalk says it is still unsure how many of its four million customers have been affected by the attack but have warned personal details such as credit card and bank details may have been accessed.
What data may have been compromised?
Dates of birth
TalkTalk account information
Credit card details and/or bank details
TalkTalk says no money can be taken from bank accounts using the information but there is a risk the data could be use for identity fraud.
It has contacted all major banks who will be monitoring for any suspicious activity on their customers' accounts.
They are also looking to organise a year's free credit monitoring for all customers, it said.
TalkTalk advises customers to:
Keep an eye on bank accounts over the next few months to look for fraudulent transactions. If you see anything unusual contact your bank and Action Fraud - the UK's national fraud and internet crime reporting centre on 0300 123 2040 or via www.actionfraud.police.uk
If you are contacted by anyone asking you for personal data or passwords (such as for your bank account) take steps to check the validity of their identity.
Check your credit report with the three main credit agencies: Call Credit, Experian and Equifax.
TalkTalk says it will never call customers and ask them to provide bank details.
It will also never:
Ask for your bank details to process a refund. If you are ever due a refund from us, we would only be able to process this if your bank details are already registered on our systems.
Call you and ask you to download software onto your computer, unless you have previously contacted TalkTalk, discussed and agreed a call back for this to take place.
Send you emails asking you to provide your full password. We will only ever ask for two digits from it to protect your security.
TalkTalk said: "We believed our systems were as secure as they could be. We work with world leading security experts and update our systems constantly.
"As soon as we realised the website was under attack, we pulled the website down in an effort to protect data. As a further precautionary measure, we contacted our customers straight away to warn them of the potential risk and provide advice on what to do.
"Unfortunately these criminals are very smart and their attacks are becoming ever more sophisticated."