Overlap in application of mortgage and bank account/credit card

SJE89

Back in August, I applied for a new bank account with HSBC as there was a joining offer and because I wanted to spread out my savings to different institutions. 

They also offered me a 0% interest rate on a credit card at the end of the application and I accepted. 

For whatever reason I didn’t hear anything from them after sending my proof documents. 

Not long after, we started looking for our first house and had a meeting set up by the EA with a mortgage advisor and we’re given an agreement in principle. 

Since then, our financial situation has improved. 

We found the house we wanted on the second viewing and our application was put through to the first lender who said they couldn’t take our application as Experian missed one of my addresses from over 15 years ago. 

Second application was accepted. 

Our offer on the house was accepted. 

It later came to my mind that I had applied for the account with HSBC and heard nothing. The mortgage advisor said that the first mortgage provider had been HSBC so they suspected that the Experian issue was also the reason. 

So I thought nothing more of it. 

A few weeks later, I start getting letters from HSBC to say that my account was open and my debit and credit card were on the way. 

In panic I called the mortgage advisor to tell them. 

They said it won’t be an issue as long as I don’t use the credit card before completion as it would be a shame now to lose the interest rate offer after it taking so long as the search was already on my file. 

But now we’ve agreed a completion date and still waiting for an exchange date, my anxiety is making me worry. 

Has anyone had anything like this before, and what issues has it caused, if any?

We’re not pushing ourselves re affordability and have chosen a property about two thirds the cost of what we were approved for, but I do have a problem with excessive worrying and anxiety over things like this.