not necessarily. you can always pay the minimum amount for a high priority transaction but mark it as RBF and if it didn't get confirmed in the next block and if you made sure that the mempool had indeed grown (eg. you can do it on
https://jochen-hoenicke.de/queue/#0,24h) then you can simply bump its fee before the next block is found to the new minimum for high priority.
keep in mind that each time you bump your fee your transaction ID changes and although majority of services that i have seen have no issue with RBF and those that had bugs have fixed it already you may want to know what kind of service you are using in case your payment is to such services for a purchase for instance, otherwise deposits in your accounts like on an exchange have no issue.
Yes, you're right and I do use RBF but I am not sure if the company I sent my funds to would accept the deposit if the transaction ID changes.
I'll ask them before about this when I deposit the next time. Also, the last time it happened. The service I sent the funds to asks you to enter the transaction ID in the field to show that you have made the payment.
And which is why I had to do CPFP to make that transaction confirmed when it didn't confirm after 10 hours because I couldn't change the tx id.
The services who don't accept the BTC directly are usually not sure what went wrong. I deposited BTC at one such service and even after 6 confirmations, my money wasn't credited in my account.
When I asked their support. They told me that the transaction needs to get confirmed. And I told them that it already has 6 confirmations and it is unreturnable at this point. And they answered that it is not confirmed at their end.
I told them that if a transaction is confirmed at one end, it is confirmed everywhere. And they told me to wait an hour.
But the good news is, the site I sent it to credited my account, even though the transaction came in very late. So, everything went well in the end.
Generally, most of the payment processors, they only care that a valid transaction was
broadcast to the network within the timeframe that they show the invoice as being "valid"... They will generally just not process your order or credit your account until that transaction is actually
confirmed.
Any service that issues an invoice for say "30 minutes" and expects that a user can guarantee
confirmation in that time frame (regardless of fee paid) is asking for trouble. As you saw, there can indeed be time periods where a block is not found for over an hour!
Sometimes, miners are just "unlucky"
I think what they're looking for is for the first fast confirmation, so they can credit the company whose using their services because they accept the payment in fiat and payment processors have to pay them the exact amount, even if the bitcoin price drops in the meantime. Which is why they don't accept multiple payments to the same address and/or delay.
But yes, it is not possible to know when your tx might get accepted, even if you pay the proper fee. But it is scary when they tell you that time has passed and your tx might get lost or returned. How would it get lost, I can never understand?
Btw guys, a new user in India forum has asked some advice on how to upgrade his Electrum wallet. Although 2 users have already given him good advice. If you guys have anything to share on the matter that might help, pls do so. Here's the link to the thread:
https://bitcointalksearch.org/topic/portable-electrum-wallet-problem-5277692