Hi @abigailb, our system uses the Royal Mail postcode finder to search for addresses, so if your previous address isn’t registered with Royal Mail you won’t be able to input it on the site. I’m really sorry about that.
This is because we're not able to bypass the use of Royal Mail's system on the site, as we use it in order to ensure that addresses entered are current and valid. We search for your credit report on the address details you give us, which is why the system won’t let you past this stage, as if you gave us the wrong address information then you might have missing or incorrect information on your credit report. Thank you and have a good evening.