Why does my Bitcoin address start with 1, 3 or bc1?
If you restored your wallet and saw a different address prefix than you remembered, that's normal: you didn't lose anything.
The prefix of your address (1, 3 or bc1) only tells you the technical format: **it does not change whether your bitcoin are safe.**
What each prefix means
Legacy addresses start with 1. Nested SegWit addresses (P2SH) start with 3. Native SegWit addresses start with bc1.
That is all the prefix describes: the address type. It does not indicate age, balance, or wallet reputation.
Why the prefix doesn't change whether your bitcoin are there
The address format does not affect where your bitcoin are. If you restore a wallet that uses a different derivation type, it may show addresses with a different prefix than what you saw before, and that does not mean your funds moved.
Source: COLDCARD · coldcard.com/docs/descriptor_export/.
What to check instead of the prefix
If you want to know whether the address is yours, check the exact address you wrote down or your wallet's diagnosis. The prefix alone is not enough to confirm that it is the correct address.
Do not compare only the first character: compare the full address.
The prefix does not tell you if that address is yours
Seeing an address that starts with 1, 3 or bc1 only confirms the format; it does not confirm that the address belongs to your wallet or that it received funds. To verify that, compare it with the address you wrote down in your diagnosis.
Source: COLDCARD · coldcard.com/docs/descriptor_export/