I am writing to report an issue with the call routing logic on my iPhone (dual-SIM configuration). Device setup SIM1: Domestic carrier (used for Cellular Data and Default Voice Line). SIM2: Overseas carrier (Data Roaming intentionally disabled to avoid unintended charges). Incident On 8 August 2026, I dialled the local emergency number from the Phone app. The keypad interface clearly showed that the active line was set to SIM1. However, the call was unexpectedly placed via SIM2. After the call, I checked the recent call details: the "SIM Line" field indicated SIM2. When I manually changed this to SIM1, the change appeared to take effect momentarily, but upon returning to the Recents list and re-entering the detail view, the line reverted to SIM2. The only workaround I found was to edit the contact info (via Edit -> Edit Contact Info) and force the Preferred Line to SIM1 (instead of "Last Used"), then save. This, however, creates an unnecessary entry for the emergency number in my Contacts - which I consider redundant and inelegant. Additional context I recall a previous emergency call on 2 Aug 2025, make under different circumstances (SIM1 had no service at that location, so the call correctly used SIM2). Although that older call no longer appears in Recents, my SIM2 carrier billing confirms it. I suspect that iOS has cached a "Last Used" preference for this specific number from that prior occasion, and that cache overrides the default line setting selected in the dialler - even then the user explicitly chooses SIM1 before dialling. Suggestion Please investigate whether emergency numbers retain a per-contact line preference that persists beyond the Recents history, and whether this cache can cause the system to ignore the user's active line selection at the time of dialling. Ideally, emergency calls should respect the line explicitly shown in the dialler.