diff --git a/src/app/api/registratura/debug-sequences/route.ts b/src/app/api/registratura/debug-sequences/route.ts
index 1024e41..4a478b2 100644
--- a/src/app/api/registratura/debug-sequences/route.ts
+++ b/src/app/api/registratura/debug-sequences/route.ts
@@ -27,7 +27,7 @@ export async function GET() {
     Array<{ key: string; num: string | null; snippet: string }>
   >(`
     SELECT key,
-           SUBSTRING(value::text FROM '"number":"([^"]+)"') AS num,
+           SUBSTRING(value::text FROM '"number": "([^"]+)"') AS num,
            SUBSTRING(value::text FROM 1 FOR 200) AS snippet
     FROM "KeyValueStore"
     WHERE namespace = 'registratura'
@@ -42,13 +42,13 @@ export async function GET() {
     Array<{ prefix: string; maxSeq: number; count: number }>
   >(`
     SELECT
-      SUBSTRING(value::text FROM '"number":"([A-Z]-[0-9]{4})-') AS prefix,
-      MAX(CAST(SUBSTRING(value::text FROM '"number":"[A-Z]-[0-9]{4}-([0-9]{5})"') AS INTEGER)) AS "maxSeq",
+      SUBSTRING(value::text FROM '"number": "([A-Z]-[0-9]{4})-') AS prefix,
+      MAX(CAST(SUBSTRING(value::text FROM '"number": "[A-Z]-[0-9]{4}-([0-9]{5})"') AS INTEGER)) AS "maxSeq",
       COUNT(*)::int AS count
     FROM "KeyValueStore"
     WHERE namespace = 'registratura'
       AND key LIKE 'entry:%'
-      AND value::text ~ '"number":"[A-Z]-[0-9]{4}-[0-9]{5}"'
+      AND value::text ~ '"number": "[A-Z]-[0-9]{4}-[0-9]{5}"'
     GROUP BY prefix
     ORDER BY prefix
   `);
@@ -58,13 +58,13 @@ export async function GET() {
     Array<{ prefix: string; maxSeq: number; count: number }>
   >(`
     SELECT
-      SUBSTRING(value::text FROM '"number":"([A-Z]{3}-[0-9]{4})-') AS prefix,
-      MAX(CAST(SUBSTRING(value::text FROM '"number":"[A-Z]{3}-[0-9]{4}-(?:IN|OUT|INT)-([0-9]{5})"') AS INTEGER)) AS "maxSeq",
+      SUBSTRING(value::text FROM '"number": "([A-Z]{3}-[0-9]{4})-') AS prefix,
+      MAX(CAST(SUBSTRING(value::text FROM '"number": "[A-Z]{3}-[0-9]{4}-(?:IN|OUT|INT)-([0-9]{5})"') AS INTEGER)) AS "maxSeq",
       COUNT(*)::int AS count
     FROM "KeyValueStore"
     WHERE namespace = 'registratura'
       AND key LIKE 'entry:%'
-      AND value::text ~ '"number":"[A-Z]{3}-[0-9]{4}-(IN|OUT|INT)-[0-9]{5}"'
+      AND value::text ~ '"number": "[A-Z]{3}-[0-9]{4}-(IN|OUT|INT)-[0-9]{5}"'
     GROUP BY prefix
     ORDER BY prefix
   `);
@@ -92,16 +92,16 @@ export async function POST() {
     INSERT INTO "RegistrySequence" (id, company, year, type, "lastSeq", "createdAt", "updatedAt")
     SELECT
       gen_random_uuid()::text,
-      SUBSTRING(value::text FROM '"number":"([A-Z])-') AS company,
-      CAST(SUBSTRING(value::text FROM '"number":"[A-Z]-([0-9]{4})-') AS INTEGER) AS year,
+      SUBSTRING(value::text FROM '"number": "([A-Z])-') AS company,
+      CAST(SUBSTRING(value::text FROM '"number": "[A-Z]-([0-9]{4})-') AS INTEGER) AS year,
       'SEQ' AS type,
-      MAX(CAST(SUBSTRING(value::text FROM '"number":"[A-Z]-[0-9]{4}-([0-9]{5})"') AS INTEGER)) AS "lastSeq",
+      MAX(CAST(SUBSTRING(value::text FROM '"number": "[A-Z]-[0-9]{4}-([0-9]{5})"') AS INTEGER)) AS "lastSeq",
       NOW(),
       NOW()
     FROM "KeyValueStore"
     WHERE namespace = 'registratura'
       AND key LIKE 'entry:%'
-      AND value::text ~ '"number":"[A-Z]-[0-9]{4}-[0-9]{5}"'
+      AND value::text ~ '"number": "[A-Z]-[0-9]{4}-[0-9]{5}"'
     GROUP BY company, year, type
   `);
 
@@ -110,22 +110,22 @@ export async function POST() {
     INSERT INTO "RegistrySequence" (id, company, year, type, "lastSeq", "createdAt", "updatedAt")
     SELECT
       gen_random_uuid()::text,
-      CASE SUBSTRING(value::text FROM '"number":"([A-Z]{3})-')
+      CASE SUBSTRING(value::text FROM '"number": "([A-Z]{3})-')
         WHEN 'BTG' THEN 'B'
         WHEN 'USW' THEN 'U'
         WHEN 'SDT' THEN 'S'
         WHEN 'GRP' THEN 'G'
-        ELSE SUBSTRING(value::text FROM '"number":"([A-Z]{3})-')
+        ELSE SUBSTRING(value::text FROM '"number": "([A-Z]{3})-')
       END AS company,
-      CAST(SUBSTRING(value::text FROM '"number":"[A-Z]{3}-([0-9]{4})-') AS INTEGER) AS year,
+      CAST(SUBSTRING(value::text FROM '"number": "[A-Z]{3}-([0-9]{4})-') AS INTEGER) AS year,
       'SEQ' AS type,
-      MAX(CAST(SUBSTRING(value::text FROM '"number":"[A-Z]{3}-[0-9]{4}-(?:IN|OUT|INT)-([0-9]{5})"') AS INTEGER)) AS "lastSeq",
+      MAX(CAST(SUBSTRING(value::text FROM '"number": "[A-Z]{3}-[0-9]{4}-(?:IN|OUT|INT)-([0-9]{5})"') AS INTEGER)) AS "lastSeq",
       NOW(),
       NOW()
     FROM "KeyValueStore"
     WHERE namespace = 'registratura'
       AND key LIKE 'entry:%'
-      AND value::text ~ '"number":"[A-Z]{3}-[0-9]{4}-(IN|OUT|INT)-[0-9]{5}"'
+      AND value::text ~ '"number": "[A-Z]{3}-[0-9]{4}-(IN|OUT|INT)-[0-9]{5}"'
     GROUP BY company, year, type
     ON CONFLICT (company, year, type)
     DO UPDATE SET "lastSeq" = GREATEST("RegistrySequence"."lastSeq", EXCLUDED."lastSeq"),
@@ -140,3 +140,69 @@ export async function POST() {
     message: "All counters reset from actual entries (both old and new format).",
   });
 }
+
+/**
+ * PATCH — Migrate old-format entries (BTG/SDT/USW/GRP) to new format (B/S/U/G).
+ * Rewrites the "number" field inside the JSONB value for matching entries.
+ */
+export async function PATCH() {
+  const session = await getAuthSession();
+  if (!session) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  // Map old 3-letter prefixes to new single-letter
+  const migrations: Array<{ old: string; new: string }> = [
+    { old: "BTG", new: "B" },
+    { old: "SDT", new: "S" },
+    { old: "USW", new: "U" },
+    { old: "GRP", new: "G" },
+  ];
+
+  const results: Array<{ prefix: string; updated: number }> = [];
+
+  for (const m of migrations) {
+    // Find entries with old-format numbers: BTG-2026-IN-00001, SDT-2026-OUT-00002, etc.
+    const entries = await prisma.$queryRawUnsafe<
+      Array<{ key: string; num: string }>
+    >(`
+      SELECT key,
+             SUBSTRING(value::text FROM '"number": "([^"]+)"') AS num
+      FROM "KeyValueStore"
+      WHERE namespace = 'registratura'
+        AND key LIKE 'entry:%'
+        AND value::text ~ '"number": "${m.old}-[0-9]{4}-(IN|OUT|INT)-[0-9]{5}"'
+    `);
+
+    let updated = 0;
+    for (const entry of entries) {
+      if (!entry.num) continue;
+
+      // Parse: SDT-2026-OUT-00001 → S-2026-00001
+      const match = entry.num.match(
+        new RegExp(`^${m.old}-(\\d{4})-(?:IN|OUT|INT)-(\\d{5})$`)
+      );
+      if (!match) continue;
+
+      const newNumber = `${m.new}-${match[1]}-${match[2]}`;
+
+      // Update the JSONB value — replace the number field
+      await prisma.$executeRawUnsafe(`
+        UPDATE "KeyValueStore"
+        SET value = jsonb_set(value, '{number}', $1::jsonb)
+        WHERE namespace = 'registratura'
+          AND key = $2
+      `, JSON.stringify(newNumber), entry.key);
+
+      updated++;
+    }
+
+    results.push({ prefix: m.old, updated });
+  }
+
+  return NextResponse.json({
+    success: true,
+    migrations: results,
+    message: "Old-format entries migrated to new format. Run POST to reset counters.",
+  });
+}
diff --git a/src/modules/registratura/services/registry-service.ts b/src/modules/registratura/services/registry-service.ts
index fcbd12a..16e2975 100644
--- a/src/modules/registratura/services/registry-service.ts
+++ b/src/modules/registratura/services/registry-service.ts
@@ -258,7 +258,8 @@ export async function allocateSequenceNumber(
 
     // New format: B-2026-00001
     // NOTE: Use [0-9] instead of \d — PostgreSQL POSIX regex may not support \d
-    const newLike = `%"number":"${companyPrefix}-${yr}-%"%`;
+    // NOTE: JSONB value::text serializes with a space after colons ("number": "...")
+    const newLike = `%"number": "${companyPrefix}-${yr}-%"%`;
     const newRegex = `${companyPrefix}-${yr}-([0-9]{5})`;
     const newMaxRows = await tx.$queryRaw<Array<{ maxSeq: number | null }>>`
       SELECT MAX(
@@ -274,7 +275,7 @@ export async function allocateSequenceNumber(
     // Old format: BTG-2026-IN-00001 / BTG-2026-OUT-00001
     let oldMax = 0;
     if (oldPrefix) {
-      const oldLike = `%"number":"${oldPrefix}-${yr}-%"%`;
+      const oldLike = `%"number": "${oldPrefix}-${yr}-%"%`;
       const oldRegex = `${oldPrefix}-${yr}-(?:IN|OUT|INT)-([0-9]{5})`;
       const oldMaxRows = await tx.$queryRaw<Array<{ maxSeq: number | null }>>`
         SELECT MAX(
@@ -335,7 +336,8 @@ export async function recalculateSequence(
 
   // Find max from new format (B-2026-00001)
   // NOTE: Use [0-9] instead of \d — PostgreSQL POSIX regex may not support \d
-  const newLike = `%"number":"${companyPrefix}-${yr}-%"%`;
+  // NOTE: JSONB value::text serializes with a space after colons ("number": "...")
+  const newLike = `%"number": "${companyPrefix}-${yr}-%"%`;
   const newRegex = `${companyPrefix}-${yr}-([0-9]{5})`;
   const newRows = await prisma.$queryRaw<Array<{ maxSeq: number | null }>>`
     SELECT MAX(
@@ -350,7 +352,7 @@ export async function recalculateSequence(
 
   // Also check old format (BTG-2026-OUT-00001)
   if (oldPrefix) {
-    const oldLike = `%"number":"${oldPrefix}-${yr}-%"%`;
+    const oldLike = `%"number": "${oldPrefix}-${yr}-%"%`;
     const oldRegex = `${oldPrefix}-${yr}-(?:IN|OUT|INT)-([0-9]{5})`;
     const oldRows = await prisma.$queryRaw<Array<{ maxSeq: number | null }>>`
       SELECT MAX(