Is xmr.to fast enough for 15 minute time window on bitpay.com?

Question

I guess there are no guarantees, but how long does it take on average until bitpay.com gets the money (in the sense of having enough confirmations), starting to count time at the moment when I executed the transfer command in simplewallet?

I'm asking because with monero's 2 minute blocks and bitcoins 10 minute blocks, I can't expect the average time to be better than 12 minutes, but bitpay.com allows me only 15 minutes before the invoice expires. So there's only 3 minutes margin, and if xmr.to doesn't pay significant fees for the bitcoin transfer I assume the bitcoin transaction will not be fast enough given the congestion on the bitcoin network.

Answer 1

To add to expez's answer, BitPay should already stop the 15 minute countdown once it's found the broadcasted Bitcoin transaction.

To my knowledge some services that use BitPay require confirmation(s) but it shouldn't be an issue as the invoice shouldn't expire after the tx has been broadcast (but not yet confirmed).

Answer 2

IIRC xmr.to scans the memory pool, so they can send the transaction ASAP, without waiting for a block to be mined, so they're not going to be the bottleneck here.

That being said, remember that blocktimes such as 10 mins are target values. The time to mine any specific block is random. Sometimes it takes 20 minutes to mine a Bitcoin block, sometimes it only takes 5.

Another issue to consider is proving you sent the transaction to Bitpay in case of a dispute / timeout / mistake. To do that, for this use case, you'd have to involve xmr.to.

The guys over at xmr.to are wonderful, but you're potentially setting yourself--and them--up for quite a bit of hassle.