Yes that’s correct. I’ve done a few of these tickets with many many changes, in my experience you’ll get charged the £35 admin fee for making a change and the tax difference, but the taxes quoted often seem to be 15-20% more than you’d expect - who knows what calculations they’re using behind the scenes…

anyway, it sounds like worst case scenario you’d expect about a £65-80 GBP difference if using that logic.

If that’s ok with you, get them to go ahead and start the reissuing process. And if you don’t hear, chase them. Unfortunately not all agents are that familiar with these tickets. I’ve had to talk a few through them and the processes etc.