Typically speaking you aren't supposed to open any new accounts within 13 months of applying for a mortgage but there are exceptions. In 2021 I had NO idea I wasn't going to renew my lease on my apartment and buy a house instead. I hated my car and in November 2020 bought a new one. Previous loan was paid off early and new loan wasn't upside down from the get go. Then in January my laptop turned in its resignation and I had to get a new one. Hello new Dell account. The good news is it was 0% interest and a limit of $4k but I only spent $900 on the computer. Then comes the end of February and rents were going up (though my increase was only going to be $25 it would still have put me at around $2k/month with pet fees, community utilities etc.) and an agent I hired to help me find a rental home suggested buying since I had a VA loan. She brought in an amazing broker and within 20 minutes found out my DTI was 29%, I had been practicing AZEO already for better scores, I was more than 3 years post BK filing/discharge, and had more than enough middle mortgage score to qualify. I was approved for $400k. Found a house for less than $300k and closed in 29 days.
The new account should not be a deal breaker with a middle score of 752 puts you in the top category and even if your score drops temporarily you are still qualified for a mortgage. My suggestion is charge NOTHING on that account until you close. Now that you are in the active search and purchase phase you do not want to throw your DTI off at all. If you close quickly like I did then they may not even pull your credit again. (mine didn't she actually said I could run my cards up and it wouldn't have stopped my mortgage) If you are building or it takes a while to get an offer accepted then they may have to pull again but by then your points should have recovered if you haven't run the balances up and stick to AZEO.
My experience is that the mortgage scores are extra sensitive to new credit. Considering how important a mortgage is, I would wait until I was sure the new account has been reported to all 3 burueas and spring for a new 3B at MF (you get a discount as a member) to see what happened to the mortgage scores. Keep in mind that only your FICO 8s get updated throughout the month and you can't ever be sure the mortgage scores will move like the version 8 scores. Once you know the impact to your middle score, you can then reach out to your LO with your new scores and ask if there should be concern.
