diff --git a/quicktill/tillweb/templates/tillweb/stockline-continuous.html b/quicktill/tillweb/templates/tillweb/stockline-continuous.html
index ff30607..3ed9944 100644
--- a/quicktill/tillweb/templates/tillweb/stockline-continuous.html
+++ b/quicktill/tillweb/templates/tillweb/stockline-continuous.html
@@ -28,6 +28,9 @@
 <button class="btn btn-secondary mb-2" type="button" data-toggle="modal" data-target="#changeModal">
   Change details
 </button>
+<button class="btn btn-secondary mb-2" type="button" data-toggle="modal" data-target="#changeLineTypeModal">
+  Change line type
+</button>
 <div class="modal fade" id="changeModal" tabindex="-1" aria-labelledby="changeModalLabel" aria-hidden="true">
   <div class="modal-dialog modal-lg">
     <div class="modal-content">
@@ -59,6 +62,37 @@ <h5 class="modal-title" id="changeModalLabel">Edit stock line</h5>
     </div>
   </div>
 </div>
+<div class="modal fade" id="changeLineTypeModal" tabindex="-1" aria-labelledby="changeLineTypeModalLabel" aria-hidden="true">
+  <div class="modal-dialog modal-lg">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h5 class="modal-title" id="changeLineTypeModalLabel">Change line type</h5>
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+          <span aria-hidden="true">&times;</span>
+        </button>
+      </div>
+      <form action="" method="post">{% csrf_token %}
+        <div class="modal-body">
+          <p>This is currently a continuous stock line — all stock
+            items of the specified type are available for sale, and
+            the till will switch from one to the next when the first
+            one is used up.</p>
+          <p>You can choose to change this to a regular stock line —
+            you will need to tell the till explicitly when a stock
+            item is put on sale and when it is finished.</p>
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-dismiss="modal">
+            Cancel
+          </button>
+          <button class="btn btn-primary" type="submit" name="submit_conv_regular">
+            Change to regular stock line
+          </button>
+        </div>
+      </form>
+    </div>
+  </div>
+</div>
 {% endif %}
 
 {% if stockline.stocktype.stockonsale %}
diff --git a/quicktill/tillweb/templates/tillweb/stockline-display.html b/quicktill/tillweb/templates/tillweb/stockline-display.html
index 6bde863..31167a0 100644
--- a/quicktill/tillweb/templates/tillweb/stockline-display.html
+++ b/quicktill/tillweb/templates/tillweb/stockline-display.html
@@ -29,33 +29,70 @@
 <button class="btn btn-secondary mb-2" type="button" data-toggle="modal" data-target="#changeModal">
   Change details
 </button>
+<button class="btn btn-secondary mb-2" type="button" data-toggle="modal" data-target="#changeLineTypeModal">
+  Change line type
+</button>
 <div class="modal fade" id="changeModal" tabindex="-1" aria-labelledby="changeModalLabel" aria-hidden="true">
   <div class="modal-dialog modal-lg">
     <div class="modal-content">
       <div class="modal-header">
-	<h5 class="modal-title" id="changeModalLabel">Edit stock line</h5>
-	<button type="button" class="close" data-dismiss="modal" aria-label="Close">
-	  <span aria-hidden="true">&times;</span>
-	</button>
+        <h5 class="modal-title" id="changeModalLabel">Edit stock line</h5>
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+          <span aria-hidden="true">&times;</span>
+        </button>
+      </div>
+      <form action="" method="post">{% csrf_token %}
+        <div class="modal-body">
+          {% include "form-horizontal.html" %}
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-dismiss="modal">
+            Cancel
+          </button>
+          <button class="btn btn-danger" type="submit" name="submit_delete" formnovalidate{% if stockline.stockonsale %} disabled{% endif %}>
+            Delete stock line
+          </button>
+          <button class="btn btn-primary" type="submit" name="submit_update">
+            Update stock line
+          </button>
+        </div>
+        <datalist id="locations">
+          {% for l in locations %}<option value="{{l}}">{% endfor %}
+        </datalist>
+      </form>
+    </div>
+  </div>
+</div>
+<div class="modal fade" id="changeLineTypeModal" tabindex="-1" aria-labelledby="changeLineTypeModalLabel" aria-hidden="true">
+  <div class="modal-dialog modal-lg">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h5 class="modal-title" id="changeLineTypeModalLabel">Change line type</h5>
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+          <span aria-hidden="true">&times;</span>
+        </button>
       </div>
       <form action="" method="post">{% csrf_token %}
-	<div class="modal-body">
-	  {% include "form-horizontal.html" %}
-	</div>
-	<div class="modal-footer">
-	  <button type="button" class="btn btn-secondary" data-dismiss="modal">
-	    Cancel
-	  </button>
-	  <button class="btn btn-danger" type="submit" name="submit_delete" formnovalidate{% if stockline.stockonsale %} disabled{% endif %}>
-	    Delete stock line
-	  </button>
-	  <button class="btn btn-primary" type="submit" name="submit_update">
-	    Update stock line
-	  </button>
-	</div>
-	<datalist id="locations">
-	  {% for l in locations %}<option value="{{l}}">{% endfor %}
-	</datalist>
+        <div class="modal-body">
+          <p>This is currently a display stock line — multiple stock
+            items of a particular type are on sale, and the till keeps
+            track of how many are in storage and how many are on
+            display and ready to sell.</p>
+          <p>You can choose to change this to a continuous stock line
+            — all items of that type will be available for use and the
+            till will switch from one to the next when the first is
+            used up. The till won't keep track of how many items are
+            on display and ready to sell, it will assume that all
+            items are ready for sale.</p>
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-dismiss="modal">
+            Cancel
+          </button>
+          <button class="btn btn-primary" type="submit" name="submit_conv_continuous">
+            Change to continuous stock line
+          </button>
+        </div>
       </form>
     </div>
   </div>
diff --git a/quicktill/tillweb/templates/tillweb/stockline-regular.html b/quicktill/tillweb/templates/tillweb/stockline-regular.html
index 72c1396..1cc44ab 100644
--- a/quicktill/tillweb/templates/tillweb/stockline-regular.html
+++ b/quicktill/tillweb/templates/tillweb/stockline-regular.html
@@ -27,33 +27,73 @@
 <button class="btn btn-secondary mb-2" type="button" data-toggle="modal" data-target="#changeModal">
   Change details
 </button>
+<button class="btn btn-secondary mb-2" type="button" data-toggle="modal" data-target="#changeLineTypeModal">
+  Change line type
+</button>
 <div class="modal fade" id="changeModal" tabindex="-1" aria-labelledby="changeModalLabel" aria-hidden="true">
   <div class="modal-dialog modal-lg">
     <div class="modal-content">
       <div class="modal-header">
-	<h5 class="modal-title" id="changeModalLabel">Edit stock line</h5>
-	<button type="button" class="close" data-dismiss="modal" aria-label="Close">
-	  <span aria-hidden="true">&times;</span>
-	</button>
+        <h5 class="modal-title" id="changeModalLabel">Edit stock line</h5>
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+          <span aria-hidden="true">&times;</span>
+        </button>
+      </div>
+      <form action="" method="post">{% csrf_token %}
+        <div class="modal-body">
+          {% include "form-horizontal.html" %}
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-dismiss="modal">
+            Cancel
+          </button>
+          <button class="btn btn-danger" type="submit" name="submit_delete" formnovalidate{% if stockline.stockonsale %} disabled{% endif %}>
+            Delete stock line
+          </button>
+          <button class="btn btn-primary" type="submit" name="submit_update">
+            Update stock line
+          </button>
+        </div>
+        <datalist id="locations">
+          {% for l in locations %}<option value="{{l}}">{% endfor %}
+        </datalist>
+      </form>
+    </div>
+  </div>
+</div>
+<div class="modal fade" id="changeLineTypeModal" tabindex="-1" aria-labelledby="changeLineTypeModalLabel" aria-hidden="true">
+  <div class="modal-dialog modal-lg">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h5 class="modal-title" id="changeLineTypeModalLabel">Change line type</h5>
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+          <span aria-hidden="true">&times;</span>
+        </button>
       </div>
       <form action="" method="post">{% csrf_token %}
-	<div class="modal-body">
-	  {% include "form-horizontal.html" %}
-	</div>
-	<div class="modal-footer">
-	  <button type="button" class="btn btn-secondary" data-dismiss="modal">
-	    Cancel
-	  </button>
-	  <button class="btn btn-danger" type="submit" name="submit_delete" formnovalidate{% if stockline.stockonsale %} disabled{% endif %}>
-	    Delete stock line
-	  </button>
-	  <button class="btn btn-primary" type="submit" name="submit_update">
-	    Update stock line
-	  </button>
-	</div>
-	<datalist id="locations">
-	  {% for l in locations %}<option value="{{l}}">{% endfor %}
-	</datalist>
+        <div class="modal-body">
+          <p>This is currently a regular stock line — a single stock
+            item is on sale at once and you must tell the till with the
+            Use Stock function when you change to a new item.</p>
+          <p>You can choose to change this to a continuous stock line
+            — all items of a particular type will be available for use
+            and the till will switch from one to the next when the
+            first is used up.</p>
+          {% if not stockline.stockonsale and not stockline.stocktype %}
+          <div class="alert alert-warning">You must either put an item
+            on sale or change the stock line to restrict items to a
+            particular stock type before you can change this to be a
+            continuous stock line.</div>
+          {% endif %}
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-dismiss="modal">
+            Cancel
+          </button>
+          <button class="btn btn-primary" type="submit" name="submit_conv_continuous"{% if not stockline.stockonsale and not stockline.stocktype %} disabled{% endif %}>
+            Change to continuous stock line
+          </button>
+        </div>
       </form>
     </div>
   </div>
diff --git a/quicktill/tillweb/views.py b/quicktill/tillweb/views.py
index 5a23ad1..c673f9b 100644
--- a/quicktill/tillweb/views.py
+++ b/quicktill/tillweb/views.py
@@ -3,7 +3,7 @@
 from django.http import JsonResponse
 from django.contrib.auth.decorators import login_required
 from django.contrib import messages
-from django.shortcuts import render
+from django.shortcuts import render, redirect
 from django.template.loader import render_to_string
 from django.conf import settings
 from django import forms
@@ -2118,6 +2118,7 @@ def stockline_regular(request, info, s):
                 s.stocktype = cd['stocktype']
                 s.department = cd['department']
                 s.pullthru = cd['pullthru']
+                user.log(f"Updated stock line {s.logref}")
                 try:
                     td.s.commit()
                     messages.success(request, "Stock line updated")
@@ -2133,6 +2134,22 @@ def stockline_regular(request, info, s):
             td.s.commit()
             messages.success(request, "Stock line deleted")
             return HttpResponseRedirect(info.reverse("tillweb-stocklines"))
+        elif request.method == 'POST' \
+             and 'submit_conv_continuous' in request.POST:  # noqa: E127
+            if not s.stockonsale and not s.stocktype:
+                messages.error(request, "Could not change line type")
+                return redirect(s)
+            for si in list(s.stockonsale):
+                si.stockline = None
+                s.pullthru = None
+                s.department = None
+                s.stocktype = si.stocktype
+            messages.success(request, "Stock line converted to Continuous")
+            user.log(f"Converted stock line {s.logref} from Regular to "
+                     f"Continuous, selling {s.stocktype.logref}")
+            s.linetype = "continuous"
+            td.s.commit()
+            return redirect(s)
         else:
             form = RegularStockLineForm(info, initial={
                 "name": s.name,
@@ -2212,6 +2229,18 @@ def stockline_display(request, info, s):
             td.s.commit()
             messages.success(request, "Stock line deleted")
             return HttpResponseRedirect(info.reverse("tillweb-stocklines"))
+        elif request.method == 'POST' \
+             and 'submit_conv_continuous' in request.POST:  # noqa: E127
+            for si in list(s.stockonsale):
+                si.stockline = None
+                si.displayqty = None
+            s.capacity = None
+            s.linetype = "continuous"
+            messages.success(request, "Stock line converted to Continuous")
+            user.log(f"Converted stock line {s.logref} from Display to "
+                     f"Continuous, selling {s.stocktype.logref}")
+            td.s.commit()
+            return redirect(s)
         else:
             form = DisplayStockLineForm(info, initial={
                 "name": s.name,
@@ -2279,6 +2308,13 @@ def stockline_continuous(request, info, s):
             td.s.commit()
             messages.success(request, "Stock line deleted")
             return HttpResponseRedirect(info.reverse("tillweb-stocklines"))
+        elif request.method == 'POST' and 'submit_conv_regular' in request.POST:
+            s.linetype = "regular"
+            messages.success(request, "Stock line converted to Regular")
+            user.log(f"Converted stock line {s.logref} from Continuous to "
+                     f"Regular, selling only {s.stocktype.logref}")
+            td.s.commit()
+            return redirect(s)
         else:
             form = ContinuousStockLineForm(info, initial={
                 "name": s.name,