If the ring does not go on when you propose, do not force it. Leave it in the box, or let your partner hold it, and treat the fit as something to settle later. A ring that will not pass a knuckle in that moment is a sizing question, not a verdict on the proposal.
This happens more often than people expect, especially with a surprise. Hands change through the day, and a size that was carefully estimated can still feel tight after a walk, a meal, or in cold or very warm weather. The kindest thing you can do is stay calm and keep the ring safe.
Why a ring can refuse a finger on the day
Fingers are not a fixed measurement. They can look slimmer in the cold and fuller when they are warm, after exercise, after salty food, or when someone has been nervous for hours. A ring that was close to size in a quieter moment may not slide over the knuckle at sunset, or in a heated restaurant. That is why, when a proposal is a surprise, we talk through how to estimate a size in advance, including our guide to finding a ring size without ruining the surprise. Even a careful estimate can be a little off, and the day itself can add a little swelling or tightness on top.

Do not force it, and do not let the moment narrow to the knuckle
Forcing a ring over a tight knuckle can hurt, and it can also get the ring stuck, which is a much more awkward problem than a ring that simply will not go on. If it does not pass easily, stop. Your partner can hold the box, or you can put the ring away and come back to it later in the evening, once hands have settled. Some people like to wear the ring on a secure chain for a day or two, which is a perfectly decent temporary option, though it should be taken off for swimming or showering and is not a substitute for a proper resize.
If they would rather put the ring on themselves, that is often easier, because they can feel how the knuckle is behaving. Our note on why engagement rings are often worn on the left hand is about custom, not about a requirement. If the usual finger is not comfortable that day, another finger can hold the ring for an evening.

What happens afterwards, including a resize
When you are home, you can check the size more calmly. Our guide to checking a UK ring size at home explains methods without turning the evening into a measuring exercise. If the ring was commissioned with us and the design can be resized, we include one free resize within 1 month. Not every design can be resized, which is something we discuss when the CAD is agreed in writing. If a resize is needed, get in touch and we will talk you through it. We work by video consultation and message, with no showroom.
The wider practical list, including insurance and photographs of the ring for your records, is in our guide to what to do after getting engaged. None of that has to be done in the first hour. If you are still at the commissioning stage and are worried about size before the ring is made, we can talk it through while we look at stones in our diamond collection. Making then takes 5 to 6 weeks after written approval of the CAD and the stone.
Frequently asked questions
What should you do if the ring does not go on when you propose?
Do not force it. Leave the ring in its box or rest it gently, enjoy the moment, and treat the fit as something to settle later. A ring that will not pass a knuckle on the day is a sizing question, not a failed proposal.
Why might a ring that was sized carefully still feel tight on the day?
Hands change with temperature, salt, a long walk, a meal, or nerves. Cold fingers can be slimmer, and warm or slightly swollen fingers can be fuller, so a ring that was close in size may not slide on at that particular moment.
Is it all right for them to wear the ring on a chain until it is resized?
Yes, if they would like to, and if the chain is secure. It is a temporary way to have the ring with them. It should not be worn in water, and it is not a substitute for a proper resize once you are home.
Will you resize a ring if it does not fit after a surprise proposal?
Yes, if the design can be resized. We include one free resize within 1 month, provided the design allows it. Some styles, including many full eternity bands, cannot be resized in the same way, which we will have discussed when the design was agreed.