diff --git a/crates/socket-patch-core/src/crawlers/gradle_cache.rs b/crates/socket-patch-core/src/crawlers/gradle_cache.rs
index 5f8dfcace..8774a0f6e 100644
--- a/crates/socket-patch-core/src/crawlers/gradle_cache.rs
+++ b/crates/socket-patch-core/src/crawlers/gradle_cache.rs
@@ -702,7 +702,7 @@ const WRAPPER_PROPERTIES: &str = "gradle/wrapper/gradle-wrapper.properties";
 /// `\r`, `\f`, `\uXXXX` and `\<char>` escapes are resolved. A later key
 /// wins.
 fn parse_properties(bytes: &[u8]) -> HashMap<String, String> {
-    let bytes = bytes.strip_prefix(b"\xEF\xBB\xBF").unwrap_or(bytes);
+    let bytes = crate::formats::text::strip_bom_bytes(bytes);
     let text: String = bytes.iter().map(|&b| b as char).collect();
     let text = text.replace("\r\n", "\n");
     let is_ws = |c: char| matches!(c, ' ' | '\t' | '\x0c');
@@ -1010,3 +1010,23 @@ pub fn locked_gavs(cwd: &Path) -> BTreeSet<Gav> {
     }
     out
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// `Properties.load` drops one leading UTF-8 BOM (#905); the bytes of a
+    /// second one are ISO-8859-1 content of the first key.
+    #[test]
+    fn parse_properties_drops_one_leading_bom_only() {
+        let one = parse_properties(b"\xef\xbb\xbfdistributionUrl=x\n");
+        assert_eq!(one.get("distributionUrl").map(String::as_str), Some("x"));
+        let two = parse_properties(b"\xef\xbb\xbf\xef\xbb\xbfdistributionUrl=x\n");
+        assert_eq!(two.get("distributionUrl"), None);
+        assert_eq!(
+            two.get("\u{ef}\u{bb}\u{bf}distributionUrl")
+                .map(String::as_str),
+            Some("x")
+        );
+    }
+}
diff --git a/crates/socket-patch-core/src/crawlers/ivy_cache.rs b/crates/socket-patch-core/src/crawlers/ivy_cache.rs
index 3df844893..5ae6fbcca 100644
--- a/crates/socket-patch-core/src/crawlers/ivy_cache.rs
+++ b/crates/socket-patch-core/src/crawlers/ivy_cache.rs
@@ -295,7 +295,7 @@ fn attribute<'a>(tag: &'a str, name: &str) -> Option<&'a str> {
 /// Whether `text`'s root element is `<project` (after a BOM, the XML
 /// declaration, comments and a doctype).
 fn is_pom_root(text: &str) -> bool {
-    let mut rest = text.trim_start_matches('\u{feff}');
+    let mut rest = crate::formats::text::strip_bom(text);
     loop {
         rest = rest.trim_start();
         let skip_to = if rest.starts_with("<?") {
@@ -700,6 +700,9 @@ mod tests {
             "\u{feff}<?xml version=\"1.0\"?>\n<!-- a -->\n<!DOCTYPE x>\n<project xmlns=\"y\">"
         ));
         assert!(!is_pom_root("<projects>"));
+        // Exactly one leading BOM is encoding (#905); a second is content.
+        assert!(is_pom_root("\u{feff}<project>"));
+        assert!(!is_pom_root("\u{feff}\u{feff}<project>"));
         assert!(!is_pom_root("<ivy-module><project>"));
         assert!(!is_pom_root("<!-- unterminated"));
         assert!(!is_pom_root(""));
diff --git a/crates/socket-patch-core/src/formats/text.rs b/crates/socket-patch-core/src/formats/text.rs
index 88db2369f..c96a0c46b 100644
--- a/crates/socket-patch-core/src/formats/text.rs
+++ b/crates/socket-patch-core/src/formats/text.rs
@@ -66,28 +66,17 @@ mod tests {
     /// on #905 step 3 (they are changed by open PRs). Drop a file when you
     /// move it onto the helpers above.
     const PENDING_INLINE_BOMS: &[&str] = &[
-        "crawlers/gradle_cache.rs",
-        "crawlers/ivy_cache.rs",
         "crawlers/npm_crawler.rs",
         "formats/pnpm/lines.rs",
-        "formats/sbt/owned_file.rs",
-        "formats/yarn/berry_gates.rs",
-        "formats/yarn/mod.rs",
         "hosted/governing_root.rs",
-        "patch/redirect/gradle.rs",
         "patch/redirect/mod.rs",
         "patch/redirect/npmrc.rs",
-        "patch/redirect/upstream/gradle.rs",
         "patch/redirect/upstream/npm.rs",
         "patch/redirect/upstream/pypi.rs",
         "patch/redirect/vlt.rs",
-        "policy/mod.rs",
-        "vendor/common.rs",
         "vendor/go_mod_edit.rs",
         "vendor/jvm/gradle.rs",
         "vendor/lock_inventory/pypi.rs",
-        "vendor/npm_dir.rs",
-        "vendor/pypi_hatch.rs",
         "vendor/yarn_classic_lock.rs",
         "vex/discover/npm.rs",
         "vex/discover/pypi_other.rs",
@@ -99,6 +88,12 @@ mod tests {
         // `sbt_version` reads a Java properties file line by line and skips
         // a BOM on any line (its test pins a BOM after a comment line).
         "formats/sbt/build.rs",
+        // An owned sbt file with any leading BOM is `Modified`, never
+        // `Foreign`: the parser refuses to claim a file someone re-saved.
+        "formats/sbt/owned_file.rs",
+        // Output sanitizing drops U+FEFF anywhere as an invisible
+        // formatting character; it is not a leading-BOM rule.
+        "policy/mod.rs",
         // vlt cannot read a BOM lock, so the sniff refuses it unstripped.
         "vendor/vlt_lock_text.rs",
     ];
diff --git a/crates/socket-patch-core/src/formats/yarn/berry_gates.rs b/crates/socket-patch-core/src/formats/yarn/berry_gates.rs
index 4fad514c0..955b4bca7 100644
--- a/crates/socket-patch-core/src/formats/yarn/berry_gates.rs
+++ b/crates/socket-patch-core/src/formats/yarn/berry_gates.rs
@@ -197,7 +197,7 @@ pub fn yarnrc_compression_level(rc: &str) -> Option<&str> {
 /// The top-level `.yarnrc.yml` scalar `key`, when set, read as
 /// [`yarnrc_compression_level`] describes.
 pub fn yarnrc_scalar<'a>(rc: &'a str, key: &str) -> Option<&'a str> {
-    let rc = rc.strip_prefix('\u{feff}').unwrap_or(rc);
+    let rc = crate::formats::text::strip_bom(rc);
     rc.lines().find_map(|line| {
         let rest = line.strip_prefix(key)?.strip_prefix(':')?.trim();
         if let Some(quote) = rest.chars().next().filter(|c| matches!(c, '\'' | '"')) {
@@ -328,6 +328,11 @@ mod tests {
             yarnrc_compression_level("\u{feff}nodeLinker: pnp\r\n"),
             None
         );
+        // A second BOM is content (#905): the key is not at column 0.
+        assert_eq!(
+            yarnrc_compression_level("\u{feff}\u{feff}compressionLevel: 0\n"),
+            None
+        );
     }
 
     /// A trailing YAML comment is not part of the scalar (#370): yarn reads
diff --git a/crates/socket-patch-core/src/patch/redirect/gradle.rs b/crates/socket-patch-core/src/patch/redirect/gradle.rs
index 32d4880f7..ee5bb9520 100644
--- a/crates/socket-patch-core/src/patch/redirect/gradle.rs
+++ b/crates/socket-patch-core/src/patch/redirect/gradle.rs
@@ -58,6 +58,7 @@ use super::{
     bare_sha256_hex, registry_override_of_kind, DepOverride, FileEdit, RewriteResult,
     RewriteWarning,
 };
+use crate::formats::text::{split_bom, strip_bom};
 use crate::gradle::dsl::{self, is_ident, is_punct, Dsl, Tok, Token};
 use crate::gradle::eol::{eol_eq, newline_of, to_lf};
 use crate::gradle::graph::{
@@ -381,7 +382,7 @@ pub fn with_apply_line(
     let line = apply_line(dsl, prefix, digest, created);
     let nl = newline_of(text);
     let mut out = text.to_string();
-    if !out.is_empty() && !out.ends_with('\n') && out != "\u{feff}" {
+    if !strip_bom(&out).is_empty() && !out.ends_with('\n') {
         out.push_str(nl);
     }
     out.push_str(&line);
@@ -396,14 +397,10 @@ pub fn without_apply_line(text: &str, dsl: Dsl, prefix: &str) -> Option<String>
     let (start, end) = apply_line_span(text, dsl, prefix)?;
     let line_start = text[..start].rfind('\n').map_or(0, |i| i + 1);
     let lead = &text[line_start..start];
-    if !lead.trim_start_matches('\u{feff}').trim().is_empty() {
+    let (keep_bom, lead) = split_bom(lead);
+    if !lead.trim().is_empty() {
         return None;
     }
-    let keep_bom = if lead.starts_with('\u{feff}') {
-        "\u{feff}"
-    } else {
-        ""
-    };
     let mut cut_end = end;
     if text[cut_end..].starts_with("\r\n") {
         cut_end += 2;
@@ -1871,6 +1868,18 @@ mod tests {
             with_apply_line(kts, Dsl::Kotlin, "", "4567", true).as_deref(),
             Some("\u{feff}apply(from = \".socket/gradle/socket-patch.hosted.settings.gradle\") // socket-patch-hosted 4567\r\nrootProject.name = \"x\"\r\n")
         );
+        // A second BOM is content (#905): the apply line shares its line
+        // with it, so it is not cut out.
+        let two = format!("\u{feff}{kts}");
+        assert_eq!(without_apply_line(&two, Dsl::Kotlin, ""), None);
+        // A file holding only a BOM gets no blank line before the apply line.
+        assert_eq!(
+            with_apply_line("\u{feff}", Dsl::Kotlin, "", "4567", true)
+                .unwrap()
+                .split_once("apply(")
+                .map(|(head, _)| head),
+            Some("\u{feff}")
+        );
     }
 
     /// buildSrc and a literal included build get their own apply line (one
diff --git a/crates/socket-patch-core/src/patch/redirect/upstream/gradle.rs b/crates/socket-patch-core/src/patch/redirect/upstream/gradle.rs
index 4497e5d9c..cfe538933 100644
--- a/crates/socket-patch-core/src/patch/redirect/upstream/gradle.rs
+++ b/crates/socket-patch-core/src/patch/redirect/upstream/gradle.rs
@@ -150,7 +150,9 @@ pub(crate) async fn restore(
             }
             let created = apply_line_created(&text, t.dsl, &t.prefix());
             match without_apply_line(&text, t.dsl, &t.prefix()) {
-                Some(next) if created && next.trim_start_matches('\u{feff}').trim().is_empty() => {
+                Some(next)
+                    if created && crate::formats::text::strip_bom(&next).trim().is_empty() =>
+                {
                     staged.insert(t.rel.clone(), None);
                 }
                 Some(next) => {
diff --git a/crates/socket-patch-core/src/vendor/common.rs b/crates/socket-patch-core/src/vendor/common.rs
index 960860da8..37985b748 100644
--- a/crates/socket-patch-core/src/vendor/common.rs
+++ b/crates/socket-patch-core/src/vendor/common.rs
@@ -9,6 +9,7 @@ use serde_json::Value;
 use toml_edit::{DocumentMut, Item, Table};
 
 use crate::crawlers::python_crawler::canonicalize_pypi_name;
+use crate::formats::text::{split_bom, strip_bom, strip_bom_bytes};
 use crate::manifest::schema::PatchFileInfo;
 use crate::patch::apply::{
     is_safe_relative_subpath, normalize_file_path, ApplyResult, VerifyResult, VerifyStatus,
@@ -179,12 +180,12 @@ pub(crate) fn serialize_json(value: &Value, indent: &str) -> std::io::Result<Vec
 /// Node and yarn berry (`Manifest.loadFromText`'s `stripBOM`) all do —
 /// serde_json rejects one.
 pub(crate) fn parse_json_manifest(bytes: &[u8]) -> serde_json::Result<Value> {
-    serde_json::from_slice(bytes.strip_prefix(b"\xef\xbb\xbf").unwrap_or(bytes))
+    serde_json::from_slice(strip_bom_bytes(bytes))
 }
 
 /// [`parse_json_manifest`] for text already decoded as UTF-8.
 pub(crate) fn parse_json_text(text: &str) -> serde_json::Result<Value> {
-    serde_json::from_str(text.strip_prefix('\u{feff}').unwrap_or(text))
+    serde_json::from_str(strip_bom(text))
 }
 
 /// The byte layout a re-serialized JSON manifest keeps from the text it
@@ -200,7 +201,7 @@ pub(crate) fn parse_json_text(text: &str) -> serde_json::Result<Value> {
 /// with ([`majority_terminator`]; the forward vendor paths refuse such a
 /// file before this runs, so only a revert reaches that arm).
 pub(crate) struct JsonLayout {
-    bom: bool,
+    bom: &'static str,
     indent: String,
     eol: &'static str,
     trailer: String,
@@ -210,10 +211,7 @@ impl JsonLayout {
     /// The layout of `text` (a manifest's current contents).
     pub(crate) fn of(text: &str) -> Self {
         use crate::utils::line_endings::{majority_terminator, LineEndings};
-        let (bom, body) = match text.strip_prefix('\u{feff}') {
-            Some(rest) => (true, rest),
-            None => (false, text),
-        };
+        let (bom, body) = split_bom(text);
         let content = body.trim_end_matches([' ', '\t', '\r', '\n']);
         let eol = match LineEndings::of(body) {
             LineEndings::Crlf => "\r\n",
@@ -235,9 +233,7 @@ impl JsonLayout {
         pretty.pop();
         let pretty = String::from_utf8(pretty).map_err(std::io::Error::other)?;
         let mut out = String::with_capacity(pretty.len() + self.trailer.len() + 3);
-        if self.bom {
-            out.push('\u{feff}');
-        }
+        out.push_str(self.bom);
         // serde_json escapes every newline INSIDE a string value, so each
         // `\n` it emits is a line break of the layout.
         if self.eol == "\n" {
diff --git a/crates/socket-patch-core/src/vendor/npm_dir.rs b/crates/socket-patch-core/src/vendor/npm_dir.rs
index 2a3dfe5e6..1ee6fc851 100644
--- a/crates/socket-patch-core/src/vendor/npm_dir.rs
+++ b/crates/socket-patch-core/src/vendor/npm_dir.rs
@@ -183,7 +183,7 @@ fn object_members(text: &str, open: usize) -> Option<Vec<JsonMember>> {
 /// The top-level members of a JSON object document (a leading BOM is kept
 /// out of the offsets' way, never stripped from the text).
 pub(crate) fn root_members(text: &str) -> Option<Vec<JsonMember>> {
-    let body = text.strip_prefix('\u{feff}').unwrap_or(text);
+    let body = crate::formats::text::strip_bom(text);
     serde_json::from_str::<serde_json::Map<String, Value>>(body).ok()?;
     let open = skip_ws(text.as_bytes(), text.len() - body.len());
     object_members(text, open)
@@ -946,6 +946,11 @@ mod tests {
             Err(SpanError::Duplicate("devDependencies".into()))
         );
         assert_eq!(strip_dev_dependencies("[1]"), Err(SpanError::NotJson));
+        // A second BOM is content (#905): not a JSON object document.
+        assert_eq!(
+            strip_dev_dependencies("\u{feff}\u{feff}{\"devDependencies\":{}}"),
+            Err(SpanError::NotJson)
+        );
     }
 
     #[test]
diff --git a/crates/socket-patch-core/src/vendor/pypi_hatch.rs b/crates/socket-patch-core/src/vendor/pypi_hatch.rs
index 906af506a..36517ac44 100644
--- a/crates/socket-patch-core/src/vendor/pypi_hatch.rs
+++ b/crates/socket-patch-core/src/vendor/pypi_hatch.rs
@@ -364,7 +364,7 @@ pub(super) async fn revert(entry: &VendorEntry, root: &Path, dry_run: bool) -> R
 fn permission_held_by_live_references(files: &BTreeMap<String, String>) -> bool {
     files
         .get(hatch::HATCH_FILES[0])
-        .and_then(|text| text.trim_start_matches('\u{feff}').parse().ok())
+        .and_then(|text| crate::formats::text::strip_bom(text).parse().ok())
         .is_some_and(|document: toml_edit::DocumentMut| {
             crate::vendor::common::pyproject_dependency_specs(&document)
                 .into_iter()
@@ -380,8 +380,7 @@ fn permission_held_by_live_references(files: &BTreeMap<String, String>) -> bool
 /// `text` without its direct-reference permission and the tables that
 /// leaves empty, or `None` when the permission is not set there.
 fn drop_owned_permission(text: &str, file: &str) -> Option<String> {
-    let body = text.trim_start_matches('\u{feff}');
-    let bom = &text[..text.len() - body.len()];
+    let (bom, body) = crate::formats::text::split_bom(text);
     let mut document = body.parse::<toml_edit::DocumentMut>().ok()?;
     let keys = hatch::permission_keys(file == hatch::HATCH_FILES[1]);
     hatch::drop_direct_reference_permission(&mut document, keys)
@@ -413,6 +412,33 @@ mod tests {
         .unwrap()
     }
 
+    /// The permission readers split off one leading BOM (#905) and the
+    /// writer puts it back. toml_edit skips one more BOM itself, so a file
+    /// with two still parses; its second BOM is not written back.
+    #[test]
+    fn permission_readers_split_one_leading_bom() {
+        let permitted = "[tool.hatch.metadata]\nallow-direct-references = true\n";
+        let one = drop_owned_permission(&format!("\u{feff}{permitted}"), "pyproject.toml").unwrap();
+        assert!(one.starts_with('\u{feff}') && !one[3..].starts_with('\u{feff}'));
+        assert!(!one.contains("allow-direct-references"), "{one}");
+        assert_eq!(
+            drop_owned_permission(&format!("\u{feff}\u{feff}{permitted}"), "pyproject.toml")
+                .as_deref(),
+            Some("\u{feff}")
+        );
+
+        let held = |text: String| {
+            permission_held_by_live_references(&BTreeMap::from([(
+                "pyproject.toml".to_string(),
+                text,
+            )]))
+        };
+        let live = "[project]\ndependencies = [\"x @ file:///elsewhere/x.whl\"]\n";
+        assert!(held(live.to_string()));
+        assert!(held(format!("\u{feff}{live}")));
+        assert!(held(format!("\u{feff}\u{feff}{live}")));
+    }
+
     #[tokio::test]
     async fn recorded_pin_drift_missing_artifact_and_ledgerless_source() {
         let temp = tempfile::tempdir().unwrap();