You can put the engagement ring on their finger, or they can put it on themselves. Both are completely all right. What matters is that the ring is offered safely, and that nobody is trying to force a tight knuckle while the two of you are still taking the moment in.
People often worry about this more than they need to, as if there were a correct choreography. There is not. Some people like the symbolism of placing the ring. Others find that, with shaking hands or a close fit, it is kinder to hold the box and let their partner slide the ring on when they are ready.
Offering the ring, rather than completing a routine
If you want to place the ring, take it from a closed box only when you are steady enough to hold it, and give your partner a chance to straighten their hand. If the ring does not pass the knuckle easily, stop and let them try, or leave it for a few minutes. Our related guide on what to do if the ring does not go on when you propose covers that situation in more detail. The question you have just asked is not undone by a pause.

Letting them put it on themselves
Many people prefer to put the ring on themselves, even in a traditional proposal. They can feel how their knuckle is behaving, and they can choose the angle that works. That is not a less romantic option. It is often the more comfortable one, especially in the cold, or after a long walk, when fingers may not be at their usual size. You can still be the person who opens the box and holds it out. If you are proposing at home, on a sofa or in the kitchen, sitting close together can make this feel very natural, as we note in our guide to proposing at home.

Which finger, and what if the usual one is not comfortable
In the UK, an engagement ring is most often worn on the left hand ring finger, and our short guide to that custom explains the background. It is still a custom, not a requirement. If that finger is tight on the day, another finger can hold the ring for the evening, or the ring can go back in the box until you are home. You can then use our guide to checking a UK ring size at home if you need to. If the ring was made by us and the design can be resized, we include one free resize within 1 month.

You do not need a particular posture for this part
Whether you are standing, sitting, or on one knee, the ring can go on whenever you are both ready, including a minute or two after the answer. If you would like to talk through timing, packing or how a finished ring will reach you, contact us. We work by video consultation and message, with no showroom. Making takes 5 to 6 weeks after written approval of the CAD and the stone, and we send the ring by insured, tracked FedEx. If you are still choosing a stone, our diamond collection is a useful place to start, and you can share rings you like with us when you are ready.
Frequently asked questions
Should you put the engagement ring on their finger, or should they put it on themselves?
Either is fine. You can offer to place it, or you can hold the box and let them put it on, which is often easier if you are both a little shaky or if the fit is close.
Is there a correct finger for the ring in that moment?
In the UK the engagement ring is most often worn on the left hand ring finger, but that is custom rather than a rule. If that finger is not comfortable on the day, another finger can hold the ring until a resize is arranged.
What if your hands are shaking too much to place the ring?
Let them put it on, or leave it in the box and come back to it a few minutes later. There is no need to complete a perfect gesture while your hands are unsteady.
Does it matter if you are not on one knee when the ring goes on?
No. Standing, sitting or kneeling can all work. The ring can go on whenever you are both ready, including a little after the question itself.