The deadline for renewing tax credits claims was 31 July 2015.
Anyone who has not yet renewed their tax credits should do so as soon as possible as otherwise their payments may be stopped.
"In a recent press release, HMRC confirmed that more than 750,000 people renewed their tax credits online. This was almost double the amount of people that renewed online last year. The 30 July was the busiest day for online renewals when over 55,000 renewals were made," said a spokesperson.
"Claimants needed to notify HMRC of any changes to the family size, child care costs, number of hours worked and salary. Details of previous year’s income also needed to be completed on the form to allow HMRC to check if the correct tax credits have been paid.
"Claimants must also inform HMRC of any changes in circumstances not already reported during the year such as new working hours, different childcare costs or changes in pay."
Nick Lodge, HMRC’s Director General, Benefits and Credits, said:
'It’s great to see so many more people renewing online this year – and giving the service the thumbs-up. It’s really important that people renew by the deadline to ensure their payments don’t stop. If you still need to renew, you must contact us urgently.'