diff --git a/src/Api/Controllers/OrganizationsController.cs b/src/Api/Controllers/OrganizationsController.cs
index 6e0706278b..fd6f3fa284 100644
--- a/src/Api/Controllers/OrganizationsController.cs
+++ b/src/Api/Controllers/OrganizationsController.cs
@@ -128,6 +128,45 @@ namespace Bit.Api.Controllers
             await _organizationService.ReplacePaymentMethodAsync(orgIdGuid, model.PaymentToken);
         }
 
+        [HttpPut("{id}/upgrade")]
+        [HttpPost("{id}/upgrade")]
+        public async Task PutUpgrade(string id, [FromBody]OrganizationUpgradeRequestModel model)
+        {
+            var orgIdGuid = new Guid(id);
+            if(!_currentContext.OrganizationOwner(orgIdGuid))
+            {
+                throw new NotFoundException();
+            }
+
+            await _organizationService.UpgradePlanAsync(orgIdGuid, model.PlanType, model.AdditionalSeats);
+        }
+
+        [HttpPut("{id}/seat")]
+        [HttpPost("{id}/seat")]
+        public async Task PutSeat(string id, [FromBody]OrganizationSeatRequestModel model)
+        {
+            var orgIdGuid = new Guid(id);
+            if(!_currentContext.OrganizationOwner(orgIdGuid))
+            {
+                throw new NotFoundException();
+            }
+
+            await _organizationService.AdjustSeatsAsync(orgIdGuid, model.SeatAdjustment.Value);
+        }
+
+        [HttpPut("{id}/cancel")]
+        [HttpPost("{id}/cancel")]
+        public async Task PutCancel(string id, [FromBody]OrganizationSeatRequestModel model)
+        {
+            var orgIdGuid = new Guid(id);
+            if(!_currentContext.OrganizationOwner(orgIdGuid))
+            {
+                throw new NotFoundException();
+            }
+
+            await _organizationService.CancelSubscriptionAsync(orgIdGuid, true);
+        }
+
         [HttpDelete("{id}")]
         [HttpPost("{id}/delete")]
         public async Task Delete(string id)
diff --git a/src/Core/Models/Api/Request/Organizations/OrganizationSeatRequestModel.cs b/src/Core/Models/Api/Request/Organizations/OrganizationSeatRequestModel.cs
new file mode 100644
index 0000000000..055a331cdc
--- /dev/null
+++ b/src/Core/Models/Api/Request/Organizations/OrganizationSeatRequestModel.cs
@@ -0,0 +1,10 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Core.Models.Api
+{
+    public class OrganizationSeatRequestModel
+    {
+        [Required]
+        public int? SeatAdjustment { get; set; }
+    }
+}
diff --git a/src/Core/Models/Api/Request/Organizations/OrganizationUpgradeRequestModel.cs b/src/Core/Models/Api/Request/Organizations/OrganizationUpgradeRequestModel.cs
new file mode 100644
index 0000000000..63346e582d
--- /dev/null
+++ b/src/Core/Models/Api/Request/Organizations/OrganizationUpgradeRequestModel.cs
@@ -0,0 +1,12 @@
+using Bit.Core.Enums;
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Core.Models.Api
+{
+    public class OrganizationUpgradeRequestModel
+    {
+        public PlanType PlanType { get; set; }
+        [Range(0, double.MaxValue)]
+        public short AdditionalSeats { get; set; }
+    }
+}
diff --git a/src/Core/Services/IOrganizationService.cs b/src/Core/Services/IOrganizationService.cs
index 2df9a946ce..557f8f084f 100644
--- a/src/Core/Services/IOrganizationService.cs
+++ b/src/Core/Services/IOrganizationService.cs
@@ -3,6 +3,7 @@ using Bit.Core.Models.Business;
 using Bit.Core.Models.Table;
 using System;
 using System.Collections.Generic;
+using Bit.Core.Enums;
 
 namespace Bit.Core.Services
 {
@@ -11,6 +12,8 @@ namespace Bit.Core.Services
         Task<OrganizationBilling> GetBillingAsync(Organization organization);
         Task ReplacePaymentMethodAsync(Guid organizationId, string paymentToken);
         Task CancelSubscriptionAsync(Guid organizationId, bool endOfPeriod = false);
+        Task UpgradePlanAsync(Guid organizationId, PlanType plan, int additionalSeats);
+        Task AdjustSeatsAsync(Guid organizationId, int seatAdjustment);
         Task<Tuple<Organization, OrganizationUser>> SignUpAsync(OrganizationSignup organizationSignup);
         Task<OrganizationUser> InviteUserAsync(Guid organizationId, Guid invitingUserId, string email,
             Enums.OrganizationUserType type, IEnumerable<SubvaultUser> subvaults);
diff --git a/src/Core/Services/Implementations/OrganizationService.cs b/src/Core/Services/Implementations/OrganizationService.cs
index de3a5a7321..673617b22c 100644
--- a/src/Core/Services/Implementations/OrganizationService.cs
+++ b/src/Core/Services/Implementations/OrganizationService.cs
@@ -175,7 +175,7 @@ namespace Bit.Core.Services
             }
         }
 
-        public async Task UpgradePlanAsync(Guid organizationId, PlanType plan, short additionalSeats)
+        public async Task UpgradePlanAsync(Guid organizationId, PlanType plan, int additionalSeats)
         {
             var organization = await _organizationRepository.GetByIdAsync(organizationId);
             if(organization == null)
@@ -300,7 +300,7 @@ namespace Bit.Core.Services
             }
         }
 
-        public async Task AdjustAdditionalSeatsAsync(Guid organizationId, short additionalSeats)
+        public async Task AdjustSeatsAsync(Guid organizationId, int seatAdjustment)
         {
             var organization = await _organizationRepository.GetByIdAsync(organizationId);
             if(organization == null)
@@ -329,20 +329,26 @@ namespace Bit.Core.Services
                 throw new BadRequestException("Plan does not allow additional seats.");
             }
 
+            var newSeatTotal = organization.Seats + seatAdjustment;
+            if(plan.BaseSeats > newSeatTotal)
+            {
+                throw new BadRequestException($"Plan has a minimum of {plan.BaseSeats} seats.");
+            }
+
+            var additionalSeats = newSeatTotal - plan.BaseSeats;
             if(plan.MaxAdditionalSeats.HasValue && additionalSeats > plan.MaxAdditionalSeats.Value)
             {
                 throw new BadRequestException($"Organization plan allows a maximum of " +
                     $"{plan.MaxAdditionalSeats.Value} additional seats.");
             }
 
-            var planNewSeats = (short)(plan.BaseSeats + additionalSeats);
-            if(!organization.Seats.HasValue || organization.Seats.Value > planNewSeats)
+            if(!organization.Seats.HasValue || organization.Seats.Value > newSeatTotal)
             {
                 var userCount = await _organizationUserRepository.GetCountByOrganizationIdAsync(organization.Id);
-                if(userCount >= planNewSeats)
+                if(userCount > newSeatTotal)
                 {
                     throw new BadRequestException($"Your organization currently has {userCount} seats filled. Your new plan " +
-                        $"only has ({planNewSeats}) seats. Remove some users.");
+                        $"only has ({newSeatTotal}) seats. Remove some users.");
                 }
             }