diff --git a/src/index.js b/src/index.js
index 4b6aff2..50bd256 100644
--- a/src/index.js
+++ b/src/index.js
@@ -97,6 +97,8 @@ import posterminalSetOff from './store/posterminal/setOff.js';
 import posterminalSetOnAll from './store/posterminal/setOnAll.js';
 import posterminalSetOffAll from './store/posterminal/setOffAll.js';
 import posterminalGetCategoryPosterminalIds from './store/posterminal/getCategoryPosterminalIds.js';
+import posterminalFindByPairingpin from './store/posterminal/findByPairingpin.js';
+import posterminalPair from './store/posterminal/pair.js';
 import langCreate from './store/lang/create.js';
 import langDelete from './store/lang/delete.js';
 import langList from './store/lang/list.js';
@@ -328,6 +330,8 @@ export default class LibDashStore {
       setOnAll: posterminalSetOnAll(provider),
       setOffAll: posterminalSetOffAll(provider),
       getCategoryPosterminalIds: posterminalGetCategoryPosterminalIds(provider),
+      findByPairingpin: posterminalFindByPairingpin(provider),
+      pair: posterminalPair(provider),
     };
 
     this.google_auth = {
diff --git a/src/providers/mssql/index.js b/src/providers/mssql/index.js
index 8c3d1ff..3722cde 100644
--- a/src/providers/mssql/index.js
+++ b/src/providers/mssql/index.js
@@ -167,6 +167,16 @@ export class MssqlProvider {
             ALTER TABLE ledger ADD warehouse_id INT NULL;
             ALTER TABLE ledger ADD CONSTRAINT FK_ledger_warehouse FOREIGN KEY (warehouse_id) REFERENCES warehouse(id) ON DELETE NO ACTION;
         END
+
+        IF OBJECT_ID(N'dbo.posterminal', N'U') IS NOT NULL AND COL_LENGTH('posterminal', 'paired_at') IS NULL
+        BEGIN
+            ALTER TABLE posterminal ADD paired_at DATETIME2 NULL;
+        END
+
+        IF OBJECT_ID(N'dbo.posterminal', N'U') IS NOT NULL AND COL_LENGTH('posterminal', 'clientserial') IS NULL
+        BEGIN
+            ALTER TABLE posterminal ADD clientserial NVARCHAR(255) NULL;
+        END
       `);
     } catch {
       // ignore
diff --git a/src/providers/mssql/queries/posterminal.js b/src/providers/mssql/queries/posterminal.js
index 3432900..49ae4b1 100644
--- a/src/providers/mssql/queries/posterminal.js
+++ b/src/providers/mssql/queries/posterminal.js
@@ -3,7 +3,9 @@ SELECT
     id,
     name,
     token,
-    pairingpin
+    pairingpin,
+    paired_at AS pairedAt,
+    clientserial AS clientserial
 FROM posterminal
 WHERE company_id = @companyId
 ORDER BY id
@@ -15,20 +17,41 @@ SELECT
     company_id AS companyId,
     name,
     token,
-    pairingpin
+    pairingpin,
+    paired_at AS pairedAt,
+    clientserial AS clientserial
 FROM posterminal
 WHERE id = @id
 `;
 
+export const FIND_BY_PAIRINGPIN = `
+SELECT
+    id,
+    company_id AS companyId,
+    name,
+    token,
+    pairingpin,
+    paired_at AS pairedAt,
+    clientserial AS clientserial
+FROM posterminal
+WHERE pairingpin = @pairingpin
+`;
+
+export const PAIR = `
+UPDATE posterminal
+SET token = @token, paired_at = @pairedAt, clientserial = @clientserial, pairingpin = ''
+WHERE id = @id
+`;
+
 export const CREATE = `
-INSERT INTO posterminal (company_id, name, token, pairingpin)
-OUTPUT INSERTED.id, INSERTED.name, INSERTED.token, INSERTED.pairingpin
-VALUES (@companyId, @name, @token, @pairingpin)
+INSERT INTO posterminal (company_id, name, token, pairingpin, paired_at, clientserial)
+OUTPUT INSERTED.id, INSERTED.name, INSERTED.token, INSERTED.pairingpin, INSERTED.paired_at AS pairedAt, INSERTED.clientserial AS clientserial
+VALUES (@companyId, @name, @token, @pairingpin, @pairedAt, @clientserial)
 `;
 
 export const UPDATE = `
 UPDATE posterminal
-SET name = @name, token = @token, pairingpin = @pairingpin
+SET name = @name, token = @token, pairingpin = @pairingpin, paired_at = @pairedAt, clientserial = @clientserial
 WHERE id = @id AND company_id = @companyId
 `;
 
diff --git a/src/providers/mssql/schema.js b/src/providers/mssql/schema.js
index 34b6c6c..82a9c54 100644
--- a/src/providers/mssql/schema.js
+++ b/src/providers/mssql/schema.js
@@ -777,6 +777,8 @@ BEGIN
         name NVARCHAR(255) NOT NULL,
         token NVARCHAR(255) NULL,
         pairingpin NVARCHAR(50) NOT NULL,
+        paired_at DATETIME2 NULL,
+        clientserial NVARCHAR(255) NULL,
         CONSTRAINT FK_posterminal_company FOREIGN KEY (company_id) REFERENCES company(id) ON DELETE CASCADE
     );
     CREATE UNIQUE INDEX UQ_posterminal_token ON posterminal(token) WHERE token IS NOT NULL;
diff --git a/src/providers/sqlite3/index.js b/src/providers/sqlite3/index.js
index 9921ee0..fa922c4 100644
--- a/src/providers/sqlite3/index.js
+++ b/src/providers/sqlite3/index.js
@@ -413,6 +413,14 @@ export class BetterSqlite3Provider extends BetterSqlite3Executor {
           `ALTER TABLE warehouse ADD COLUMN sort INTEGER NOT NULL DEFAULT 0`,
         );
       }
+
+      const posterminalCols = this.db.pragma('table_info("posterminal")').map((c) => c.name);
+      if (posterminalCols.length > 0 && !posterminalCols.includes('paired_at')) {
+        this.db.exec(`ALTER TABLE posterminal ADD COLUMN paired_at TEXT`);
+      }
+      if (posterminalCols.length > 0 && !posterminalCols.includes('clientserial')) {
+        this.db.exec(`ALTER TABLE posterminal ADD COLUMN clientserial TEXT`);
+      }
     } catch {
       // ignore
     }
diff --git a/src/providers/sqlite3/queries/posterminal.js b/src/providers/sqlite3/queries/posterminal.js
index f33a636..5e1faf0 100644
--- a/src/providers/sqlite3/queries/posterminal.js
+++ b/src/providers/sqlite3/queries/posterminal.js
@@ -5,6 +5,7 @@ const queries = translateQueries(source, 'posterminal');
 export const {
   CREATE, DELETE_BY_COMPANY_AND_ID, GET_BY_ID, LIST_BY_COMPANY,
   LIST_CATEGORY_IDS, POSTERMINAL_IDS_BY_COMPANY, SET_OFF, SET_OFF_ALL, UPDATE,
+  FIND_BY_PAIRINGPIN, PAIR,
 } = queries;
 
 export const SET_ON = `
diff --git a/src/providers/sqlite3/schema.js b/src/providers/sqlite3/schema.js
index aefc7e4..08807cf 100644
--- a/src/providers/sqlite3/schema.js
+++ b/src/providers/sqlite3/schema.js
@@ -533,6 +533,8 @@ CREATE TABLE IF NOT EXISTS posterminal (
     name TEXT NOT NULL,
     token TEXT,
     pairingpin TEXT NOT NULL,
+    paired_at TEXT,
+    clientserial TEXT,
     FOREIGN KEY (company_id) REFERENCES company(id) ON DELETE CASCADE
 );
 CREATE UNIQUE INDEX IF NOT EXISTS UQ_posterminal_token
diff --git a/src/store/posterminal/findByPairingpin.js b/src/store/posterminal/findByPairingpin.js
new file mode 100644
index 0000000..5cb62c6
--- /dev/null
+++ b/src/store/posterminal/findByPairingpin.js
@@ -0,0 +1,22 @@
+import { FIND_BY_PAIRINGPIN as MSSQL_FIND } from '../../providers/mssql/queries/posterminal.js';
+import { FIND_BY_PAIRINGPIN as SQLITE_FIND } from '../../providers/sqlite3/queries/posterminal.js';
+import makeRunner from '../runner.js';
+
+export default function findByPairingpin(provider) {
+  const sql = provider?.dialect === 'sqlite3' ? SQLITE_FIND : MSSQL_FIND;
+
+  /**
+   * Finds a posterminal by its pairingpin.
+   *
+   * @param {string} pairingpin - The pairing pin to search for.
+   * @param {object} [tx] - Optional transaction to run within.
+   * @returns {Promise<object|null>} The posterminal row, or null if not found.
+   */
+  return async (pairingpin, tx) => {
+    if (!pairingpin) return null;
+    const result = await makeRunner(provider, tx).query(sql, {
+      pairingpin: String(pairingpin).trim(),
+    });
+    return result.rows[0] || null;
+  };
+}
diff --git a/src/store/posterminal/pair.js b/src/store/posterminal/pair.js
new file mode 100644
index 0000000..bdcc3a4
--- /dev/null
+++ b/src/store/posterminal/pair.js
@@ -0,0 +1,34 @@
+import { PAIR as MSSQL_PAIR } from '../../providers/mssql/queries/posterminal.js';
+import { PAIR as SQLITE_PAIR } from '../../providers/sqlite3/queries/posterminal.js';
+import makeRunner from '../runner.js';
+
+export default function pair(provider) {
+  const sql = provider?.dialect === 'sqlite3' ? SQLITE_PAIR : MSSQL_PAIR;
+
+  /**
+   * Completes POS device pairing for a terminal.
+   *
+   * @param {number} id - The posterminal id.
+   * @param {object} input
+   * @param {string} input.token - The auth token for the paired device.
+   * @param {string} [input.clientserial] - The client name or serial identifier.
+   * @param {string} [input.pairedAt] - Timestamp when paired.
+   * @param {object} [tx] - Optional transaction to run within.
+   * @returns {Promise<{id: number, token: string, clientserial: string|null, pairedAt: string|null}>}
+   */
+  return async (id, { token, clientserial, pairedAt }, tx) => {
+    await makeRunner(provider, tx).query(sql, {
+      id,
+      token,
+      clientserial: clientserial ?? null,
+      pairedAt: pairedAt ?? null,
+    });
+
+    return {
+      id,
+      token,
+      clientserial: clientserial ?? null,
+      pairedAt: pairedAt ?? null,
+    };
+  };
+}
diff --git a/src/store/posterminal/upsert.js b/src/store/posterminal/upsert.js
index f945d3e..cc11c6f 100644
--- a/src/store/posterminal/upsert.js
+++ b/src/store/posterminal/upsert.js
@@ -47,6 +47,8 @@ export default function upsert(provider) {
     }
     const token = input.token ?? null;
     const id = input.id ?? null;
+    const pairedAt = input.pairedAt ?? null;
+    const clientserial = input.clientserial ?? null;
 
     const runner = makeRunner(provider, tx);
     const { companyId } = await access(googleAuthId, tx);
@@ -64,9 +66,11 @@ export default function upsert(provider) {
         name,
         token,
         pairingpin,
+        pairedAt,
+        clientserial,
       });
 
-      return { id, name, token, pairingpin };
+      return { id, name, token, pairingpin, pairedAt, clientserial };
     }
 
     const created = await runner.query(createSql, {
@@ -74,6 +78,8 @@ export default function upsert(provider) {
       name,
       token,
       pairingpin,
+      pairedAt,
+      clientserial,
     });
 
     const row = created.rows[0] ?? {
@@ -81,6 +87,8 @@ export default function upsert(provider) {
       name,
       token,
       pairingpin,
+      pairedAt,
+      clientserial,
     };
 
     return {
@@ -88,6 +96,8 @@ export default function upsert(provider) {
       name: row.name,
       token: row.token,
       pairingpin: row.pairingpin,
+      pairedAt: row.pairedAt ?? null,
+      clientserial: row.clientserial ?? null,
     };
   };
 }